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Search: a000148 -id:a000148
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Number of partitions into non-integral powers.
(Formerly M1830 N0726)
+10
4
1, 2, 8, 19, 41, 78, 134, 218, 339, 506, 730, 1023, 1397, 1884, 2477, 3218, 4118, 5192, 6486, 8010, 9795, 11888, 14302, 17066, 20256, 23889, 27999, 32637, 37863, 43695, 50218, 57495, 65545, 74431, 84257, 95030, 106840, 119799, 133941, 149311, 166071
OFFSET
3,2
COMMENTS
a(n) counts the solutions to the inequality x_1^(2/3)+x_2^(2/3)+x_3^(2/3)<=n for any three integers 1<=x_1<=x_2<=x_3. - R. J. Mathar, Jul 03 2009
REFERENCES
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
B. K. Agarwala, F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216.
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216. [Annotated scanned copy]
CROSSREFS
Cf. A000148, A000160, A000234. - R. J. Mathar, Jul 03 2009
KEYWORD
nonn
EXTENSIONS
More terms from Sean A. Irvine, Oct 11 2009
STATUS
approved
Number of partitions into non-integral powers.
(Formerly M3819 N1563)
+10
3
1, 5, 12, 23, 39, 62, 91, 127, 171, 228, 294, 370, 461, 561, 677, 811, 955, 1121, 1303, 1499, 1719, 1960, 2218, 2499, 2806, 3131, 3485, 3868, 4274, 4706, 5166, 5658, 6175, 6725, 7309, 7923, 8572, 9256, 9972, 10728, 11521, 12349, 13218, 14126, 15072
OFFSET
3,2
COMMENTS
a(n) counts the solutions to the inequality x_1^(2/3) + x_2^(2/3) <= n for any two distinct integers 1 <= x_1 < x_2. - R. J. Mathar, Jul 03 2009
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216.
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216. [Annotated scanned copy]
FORMULA
a(n) = A000148(n) - floor((n/2)^(3/2)). - Seth A. Troisi, May 25 2022
MAPLE
A000327 := proc(n) local a, x1, x2 ; a := 0 ; for x1 from 1 to floor(n^(3/2)) do x2 := (n-x1^(2/3))^(3/2) ; if floor(x2) >= x1+1 then a := a+floor(x2-x1) ; fi; od: a ; end: seq(A000327(n), n=3..80) ; # R. J. Mathar, Sep 29 2009
MATHEMATICA
A000327[n_] := Module[{a, x1, x2 }, a = 0; For[x1 = 1, x1 <= Floor[ n^(3/2)], x1++, x2 = (n - x1^(2/3))^(3/2); If[Floor[x2] >= x1+1, a = a + Floor[x2 - x1]]]; a ]; Table[A000327[n], {n, 3, 80}] (* Jean-François Alcover, Feb 07 2016, after R. J. Mathar *)
A000327[n_] := Sum[Min[x1 - 1, Floor[(n - x1^(2/3))^(3/2)]], {x1, 2, Floor[n^(3/2)]}];
Table[A000327[n], {n, 3, 80}] (* Seth A. Troisi, May 25 2022 *)
CROSSREFS
KEYWORD
nonn
EXTENSIONS
More terms from R. J. Mathar, Sep 29 2009
STATUS
approved
Number of partitions into non-integral powers.
(Formerly M1595 N0622)
+10
1
1, 2, 6, 13, 24, 42, 73, 125, 204, 324, 511, 801, 1228, 1856, 2780, 4135, 6084, 8873, 12847, 18481, 26416, 37473, 52871, 74216, 103596, 143841, 198839, 273654, 374987, 511735, 695559, 941932, 1271139, 1709474, 2291195, 3061385, 4078152, 5416322
OFFSET
1,2
COMMENTS
a(n) counts the solutions to the inequality sum_{i=1,2,..} x_i^(2/3)<=n for any number of distinct integers 1<=x_1<x_2<x_3<x_4<... - R. J. Mathar, Jul 03 2009
REFERENCES
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
B. K. Agarwala, F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216.
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216. [Annotated scanned copy]
EXAMPLE
For n=3, the 6 solutions are (i) 1^(2/3)<=3. (ii) 1^(2/3)+2^(2/3)<=3. (iii) 2^(2/3)<=3. (iv) 3^(2/3)<=3. (v) 4^(2/3)<=3. (vi) 5^(2/3)<=3. - R. J. Mathar, Jul 03 2009
CROSSREFS
KEYWORD
nonn
EXTENSIONS
8 more terms from R. J. Mathar, Jul 03 2009
20 more terms from Sean A. Irvine, Sep 28 2009
STATUS
approved
Triangle read by rows arising from enumeration of partitions into non-integral powers.
+10
0
1, 2, 1, 5, 2, 1, 8, 7, 2, 1, 11, 15, 8, 2, 1, 14, 28, 19, 8, 2, 1, 18, 45, 41, 21, 8, 2, 1, 22, 70, 78, 48, 22, 8, 2, 1, 27, 100, 134, 99, 52, 22, 8, 2, 1, 31, 138, 218, 186, 111, 53, 22, 8, 2, 1
OFFSET
1,2
LINKS
B. K. Agarwala, F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216. See Table 1.
B. K. Agarwala and F. C. Auluck, Statistical mechanics and partitions into non-integral powers of integers, Proc. Camb. Phil. Soc., 47 (1951), 207-216. [Annotated scanned copy]
EXAMPLE
Triangle begins:
1,
2,1,
5,2,1,
8,7,2,1,
11,15,8,2,1,
14,28,19,8,2,1,
18,45,41,21,8,2,1,
22,70,78,48,22,8,2,1,
27,100,134,99,52,22,8,2,1,
31,138,218,186,111,53,22,8,2,1,
...
CROSSREFS
Columns include A000093, A000148, A000158, A000169.
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Jun 27 2015
STATUS
approved

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