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Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 3 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=floor(n/2), read by rows.
+10
23
1, 1, 1, 1, 1, 2, 2, 1, 2, 4, 1, 3, 8, 3, 1, 3, 12, 8, 1, 4, 18, 22, 6, 1, 4, 24, 40, 22, 1, 5, 32, 73, 66, 10, 1, 5, 40, 112, 146, 48, 1, 6, 50, 172, 292, 174, 20, 1, 6, 60, 240, 516, 448, 116, 1, 7, 72, 335, 860, 1020, 464, 36, 1, 7, 84, 440, 1340, 2016, 1360, 256
OFFSET
2,6
LINKS
Christopher Hunt Gribble and Andrew Howroyd, Rows n=2..60 of T(n,k) flattened (Rows n=2..20 from Christopher Hunt Gribble)
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 19 rows of T(n,k) are:
n\k 0 1 2 3 4 5 6 7 8 9 10
2 1 1
3 1 1
4 1 2 2
5 1 2 4
6 1 3 8 3
7 1 3 12 8
8 1 4 18 22 6
9 1 4 24 40 22
10 1 5 32 73 66 10
11 1 5 40 112 146 48
12 1 6 50 172 292 174 20
13 1 6 60 240 516 448 116
14 1 7 72 335 860 1020 464 36
15 1 7 84 440 1340 2016 1360 256
16 1 8 98 578 2010 3716 3400 1168 72
17 1 8 112 728 2890 6336 7432 3840 584
18 1 9 128 917 4046 10326 14864 10600 2920 136
19 1 9 144 1120 5502 16016 27536 25344 10600 1280
20 1 10 162 1368 7336 24066 48188 54992 31800 7080 272
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={(2^k*binomial(n-1*k, k) + ((k%2==0)+(n%2==0||k%2==0)+(k==0)) * 2^((k+1)\2)*binomial((n-1*k-(k%2)-(n%2))/2, k\2))/4}
for(n=2, 20, for(k=0, floor(n/2), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Corrected C++ program and xrefs added by Christopher Hunt Gribble, Apr 25 2015
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 5 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=n-n%2, read by rows.
+10
22
1, 2, 2, 1, 2, 4, 1, 4, 13, 10, 4, 1, 4, 23, 35, 23, 1, 6, 40, 101, 125, 54, 10, 1, 6, 58, 206, 403, 336, 106, 1, 8, 83, 392, 1056, 1438, 956, 240, 25, 1, 8, 109, 641, 2281, 4424, 4718, 2409, 473, 1, 10, 142, 1011, 4429, 11370, 17252, 14478, 6094, 1020, 70
OFFSET
2,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 2..967 (terms n=2..71 from Christopher Hunt Gribble)
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 8 rows of T(n,k) are:
.\ k 0 1 2 3 4 5 6 7 8
n
2 1 2 2
3 1 2 4
4 1 4 13 10 4
5 1 4 23 35 23
6 1 6 40 101 125 54 10
7 1 6 58 206 403 336 106
8 1 8 83 392 1056 1438 956 240 25
9 1 8 109 641 2281 4424 4718 2409 473
PROG
(C++) See Gribble link.
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 26 2015
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 3 X 3 tiles in an n X 5 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=3, 0<=k<=floor(n/3), read by rows.
+10
21
1, 2, 1, 2, 1, 4, 1, 4, 4, 1, 6, 9, 1, 6, 18, 1, 8, 28, 10, 1, 8, 42, 28, 1, 10, 57, 76, 1, 10, 76, 140, 25, 1, 12, 96, 254, 107, 1, 12, 120, 392, 321, 1, 14, 145, 600, 731, 70, 1, 14, 174, 840, 1462, 366, 1, 16, 204, 1170, 2610, 1308, 1, 16, 238, 1540, 4350, 3416, 196
OFFSET
3,2
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 11 rows of T(n,k) are:
.\ k 0 1 2 3 4
n
3 1 2
4 1 2
5 1 4
6 1 4 4
7 1 6 9
8 1 6 18
9 1 8 28 10
10 1 8 42 28
11 1 10 57 76
12 1 10 76 140 25
13 1 12 96 254 107
MATHEMATICA
T[n_, k_] := ((3^k + 1)*Binomial[n - 2k, k] + Boole[EvenQ[k] || OddQ[n]]*(3^(Quotient[(k + 1), 2]) + 3^Quotient[k, 2]) Binomial[(n - 2k - Mod[n, 2])/2, Quotient[k, 2]])/4; Table[T[n, k], {n, 3, 20}, {k, 0, Floor[n/3]}] // Flatten (* Jean-François Alcover, Oct 06 2017, after Andrew Howroyd *)
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={((3^k+1)*binomial(n-2*k, k) + (k%2==0||n%2==1) * (3^((k+1)\2)+3^(k\2)) * binomial((n-2*k-(n%2))/2, k\2))/4}
for(n=3, 20, for(k=0, floor(n/3), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 26 2015
Terms a(40) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 5 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=floor(n/4), read by rows.
+10
21
1, 1, 1, 1, 1, 2, 1, 2, 1, 3, 2, 1, 3, 4, 1, 4, 8, 1, 4, 12, 1, 5, 18, 3, 1, 5, 24, 8, 1, 6, 32, 22, 1, 6, 40, 40, 1, 7, 50, 73, 6, 1, 7, 60, 112, 22, 1, 8, 72, 172, 66, 1, 8, 84, 240, 146, 1, 9, 98, 335, 292, 10, 1, 9, 112, 440, 516, 48, 1, 10, 128, 578, 860, 174
OFFSET
4,6
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 14 rows of T(n,k) are:
.\ k 0 1 2 3 4
n
4 1 1
5 1 1
6 1 2
7 1 2
8 1 3 2
9 1 3 4
10 1 4 8
11 1 4 12
12 1 5 18 3
13 1 5 24 8
14 1 6 32 22
15 1 6 40 40
16 1 7 50 73 6
17 1 7 60 112 22
MATHEMATICA
T[n_, k_] := (2^k Binomial[n - 3k, k] + (Boole[EvenQ[k]] + Boole[EvenQ[n] || EvenQ[k]] + Boole[k == 0]) 2^Quotient[k+1, 2] Binomial[(n - 3k - Mod[k, 2] - Mod[n, 2])/2, Quotient[k, 2]])/4; Table[T[n, k], {n, 4, 20}, {k, 0, Floor[n/4]}] // Flatten (* Jean-François Alcover, Oct 06 2017, after Andrew Howroyd *)
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={(2^k*binomial(n-3*k, k) + ((k%2==0)+(n%2==0||k%2==0)+(k==0)) * 2^((k+1)\2)*binomial((n-3*k-(k%2)-(n%2))/2, k\2))/4}
for(n=2, 20, for(k=0, floor(n/4), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms extended and xrefs updated by Christopher Hunt Gribble, Apr 26 2015
Terms a(32) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 5 X 5 tiles in an n X 5 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=5, 0<=k<=floor(n/5), read by rows.
+10
21
1, 1, 1, 1, 1, 2, 1, 2, 1, 3, 1, 3, 1, 1, 4, 2, 1, 4, 4, 1, 5, 6, 1, 5, 9, 1, 6, 12, 1, 1, 6, 16, 2, 1, 7, 20, 6, 1, 7, 25, 10, 1, 8, 30, 19, 1, 8, 36, 28, 1, 1, 9, 42, 44, 3, 1, 9, 49, 60, 9, 1, 10, 56, 85, 19, 1, 10, 64, 110, 38, 1, 11, 72, 146, 66, 1
OFFSET
5,6
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 9 rows of T(n,k) are:
.\ k 0 1 2
n
5 1 1
6 1 1
7 1 2
8 1 2
9 1 3
10 1 3 1
11 1 4 2
12 1 4 4
13 1 5 6
MATHEMATICA
T[n_, k_] := (Binomial[n - 4k, k] + Boole[EvenQ[k] || OddQ[n]] Binomial[(n - 4k - Mod[n, 2])/2, Quotient[k, 2]])/2; Table[T[n, k], {n, 5, 20}, {k, 0, Quotient[n, 5]}] // Flatten (* Jean-François Alcover, Oct 06 2017, after Andrew Howroyd *)
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={(binomial(n-4*k, k) + (k%2==0||n%2==1)*binomial((n-4*k-n%2)/2, k\2))/2}
for(n=5, 20, for(k=0, (n\5), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms extended and xrefs updated by Christopher Hunt Gribble, Apr 26 2015
Terms a(27) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 4 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=n-n%2, read by rows.
+10
21
1, 2, 1, 1, 2, 2, 1, 4, 7, 3, 1, 1, 4, 13, 10, 4, 1, 6, 23, 33, 22, 6, 1, 1, 6, 34, 68, 72, 30, 6, 1, 8, 49, 139, 204, 145, 54, 8, 1, 1, 8, 65, 230, 467, 476, 269, 70, 9, 1, 10, 85, 377, 961, 1348, 1080, 472, 111, 12, 1, 1, 10, 106, 552, 1767, 3188, 3454, 2156
OFFSET
2,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 2..967 (terms n=2..127 from Christopher Hunt Gribble)
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 10 rows of T(n,k) are:
k 0 1 2 3 4 5 6 7 8 9 10
n
2 1 2 1
3 1 2 2
4 1 4 7 3 1
5 1 4 13 10 4
6 1 6 23 33 22 6 1
7 1 6 34 68 72 30 6
8 1 8 49 139 204 145 54 8 1
9 1 8 65 230 467 476 269 70 9
10 1 10 85 377 961 1348 1080 472 111 12 1
11 1 10 106 552 1767 3188 3454 2156 779 140 12
PROG
(C++) See Gribble link.
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and extended by Christopher Hunt Gribble, Apr 25 2015
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 3 X 3 tiles in an n X 4 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=3, 0<=k<=floor(n/3), read by rows.
+10
21
1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 3, 4, 1, 3, 8, 1, 4, 12, 3, 1, 4, 18, 8, 1, 5, 24, 22, 1, 5, 32, 40, 6, 1, 6, 40, 73, 22, 1, 6, 50, 112, 66, 1, 7, 60, 172, 146, 10, 1, 7, 72, 240, 292, 48, 1, 8, 84, 335, 516, 174, 1, 8, 98, 440, 860, 448, 20
OFFSET
3,6
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 13 rows of T(n,k) are:
.\ k 0 1 2 3 4 5
n
3 1 1
4 1 1
5 1 2
6 1 2 2
7 1 3 4
8 1 3 8
9 1 4 12 3
10 1 4 18 8
11 1 5 24 22
12 1 5 32 40 6
13 1 6 40 73 22
14 1 6 50 112 66
15 1 7 60 172 146 10
MATHEMATICA
T[n_, k_] := (2^k Binomial[n - 2k, k] + (Boole[EvenQ[k]] + Boole[OddQ[n] || EvenQ[k]] + Boole[k == 0]) 2^Quotient[k + 1, 2] Binomial[(n - 2k - Mod[n, 2])/2, Quotient[k, 2]])/4; Table[T[n, k], {n, 3, 20}, {k, 0, Floor[n/3]}] // Flatten (* Jean-François Alcover, Oct 06 2017, after Andrew Howroyd *)
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={(2^k*binomial(n-2*k, k) + ((k%2==0)+(n%2==1||k%2==0)+(k==0)) * 2^((k+1)\2)*binomial((n-2*k-(n%2))/2, k\2))/4}
for(n=2, 20, for(k=0, floor(n/3), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Link to C++ program and xrefs updated by Christopher Hunt Gribble, Apr 25 2015
Terms a(51) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 6 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=3*floor(n/2), read by rows.
+10
21
1, 3, 4, 1, 1, 3, 8, 3, 1, 6, 23, 33, 22, 6, 1, 1, 6, 40, 101, 125, 54, 10, 1, 9, 68, 262, 534, 532, 276, 74, 12, 1, 1, 9, 98, 509, 1551, 2505, 2196, 971, 219, 20, 1, 12, 139, 927, 3731, 8772, 12069, 9506, 4366, 1160, 179, 16, 1, 1, 12, 182, 1479, 7644, 24024
OFFSET
2,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 2..953 (terms n=2..69 from Christopher Hunt Gribble)
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 6 rows of T(n,k) are:
.\ k 0 1 2 3 4 5 6 7 8 9
n
2 1 3 4 1
3 1 3 8 3
4 1 6 23 33 22 6 1
5 1 6 40 101 125 54 10
6 1 9 68 262 534 532 276 74 12 1
7 1 9 98 509 1551 2505 2196 971 219 20
PROG
(C++) See Gribble link.
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 26 2015
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 6 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=floor(n/4), read by rows.
+10
21
1, 2, 1, 2, 1, 4, 1, 4, 1, 6, 4, 1, 6, 9, 1, 8, 18, 1, 8, 28, 1, 10, 42, 10, 1, 10, 57, 28, 1, 12, 76, 76, 1, 12, 96, 140, 1, 14, 120, 254, 25, 1, 14, 145, 392, 107, 1, 16, 174, 600, 321, 1, 16, 204, 840, 731, 1, 18, 238, 1170, 1462, 70, 1, 18, 273, 1540, 2610, 366
OFFSET
4,2
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 14 rows of T(n,k) are:
.\ k 0 1 2 3 4
n
4 1 2
5 1 2
6 1 4
7 1 4
8 1 6 4
9 1 6 9
10 1 8 18
11 1 8 28
12 1 10 42 10
13 1 10 57 28
14 1 12 76 76
15 1 12 96 140
16 1 14 120 254 25
17 1 14 145 392 107
MATHEMATICA
T[n_, k_] := ((3^k + 1) Binomial[n - 3k, k] + Boole[EvenQ[k] || EvenQ[n]]*(3^Quotient[k + 1, 2] + 3^Quotient[k, 2]) * Binomial[(n - 3k - Mod[k, 2] - Mod[n, 2])/2, Quotient[k, 2]])/4; Table[T[n, k], {n, 4, 20}, {k, 0, Floor[n/4]}] // Flatten (* Jean-François Alcover, Oct 06 2017, after Andrew Howroyd *)
PROG
(C++) See Gribble link.
(PARI)
T(n, k)={((3^k+1)*binomial(n-3*k, k) + (k%2==0||n%2==0) * (3^((k+1)\2)+3^(k\2)) * binomial((n-3*k-(k%2)-(n%2))/2, k\2))/4}
for(n=4, 20, for(k=0, floor(n/4), print1(T(n, k), ", ")); print) \\ Andrew Howroyd, May 29 2017
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 27 2015
Terms a(28) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved
Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 7 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=3*floor(n/2), read by rows.
+10
21
1, 3, 6, 2, 1, 3, 12, 8, 1, 6, 34, 68, 72, 30, 6, 1, 6, 58, 206, 403, 336, 106, 1, 9, 98, 509, 1551, 2505, 2196, 971, 219, 20, 1, 9, 140, 980, 4248, 10592, 15614, 12876, 5462, 900, 1, 12, 198, 1742, 9748, 33644, 73274, 98779, 80661, 37886, 9679, 1258, 72
OFFSET
2,2
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 6 rows of T(n,k) are:
./ k 0 1 2 3 4 5 6 7 8 9
n
2 1 3 6 2
3 1 3 12 8
4 1 6 34 68 72 30 6
5 1 6 58 206 403 336 106
6 1 9 98 509 1551 2505 2196 971 219 20
7 1 9 140 980 4248 10592 15614 12876 5462 900
PROG
(C++) See Gribble link.
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 27 2015
STATUS
approved

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