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a(n) = A001672(n) - A115239(n).
+20
1
0, 0, 3, 10, 33, 104, 328, 1031, 3241, 10183, 31991, 100503, 315740, 991928, 3116234, 9789941, 30756009, 96622854, 303549648, 953629346, 2995914948, 9411944394, 29568495367, 92892167824, 291829352014, 916808948392, 2880240257014
OFFSET
1,3
LINKS
EXAMPLE
a(5) = A001672(5) - A115239(5) = 306 - 273 = 33.
MATHEMATICA
a[1] = Floor[Pi]; a[n_] := a[n] = Floor[a[n - 1]*Pi]; Array[ Floor[Pi^# ] - a[ # ] &, 27] (* Robert G. Wilson v *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Hieronymus Fischer, Jan 17 2006
EXTENSIONS
More terms from Robert G. Wilson v, Jan 18 2006
STATUS
approved
Merged values of A014217 = {floor(((1+sqrt(5))/2)^n)}, A000149 = {floor(e^n)}, and A001672 = {floor(Pi^n)}, with multiplicity.
+20
0
1, 1, 1, 1, 2, 2, 3, 4, 6, 7, 9, 11, 17, 20, 29, 31, 46, 54, 76, 97, 122, 148, 199, 306, 321, 403, 521, 842, 961, 1096, 1364, 2206, 2980, 3020, 3571, 5777, 8103, 9349, 9488, 15126, 22026, 24476
OFFSET
0,5
EXAMPLE
a(8)=6 because floor(((1+sqrt(5))/2)^4)=6, a(9)=7 because floor(e^2)=7 and a(10)=9 because floor(Pi^2)=9.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by M. F. Hasler, May 29 2018
STATUS
approved
a(n) is the smallest integer > a(n-1) such that {Pi^a(n)} < {Pi^a(n-1)}, where {x} = x - floor(x), a(1)=1.
+10
12
1, 3, 81, 264, 281, 472, 1147, 2081, 3207, 3592, 10479, 12128, 65875, 114791, 118885
OFFSET
1,2
COMMENTS
The sequence was suggested by Leroy Quet on Pi day 2008, cf. A138324.
The next such number must be greater than 100000. - Hieronymus Fischer, Jan 06 2009
a(16) > 300,000. - Robert Price, Mar 25 2019
EXAMPLE
a(3)=81, since {Pi^81}=0.0037011283.., but {Pi^k}>=0.0062766802... for 1<=k<=80; thus {Pi^81}<{Pi^k} for 1<=k<81. - Hieronymus Fischer, Jan 06 2009
MATHEMATICA
$MaxExtraPrecision = 10000;
p = .999;
Select[Range[1, 5000],
If[FractionalPart[Pi^#] < p, p = FractionalPart[Pi^#]; True] &] (* Robert Price, Mar 12 2019 *)
PROG
(PARI) default(realprecision, 10^4); print1(a=1); for(i=1, 100, f=frac(Pi^a); until( frac(Pi^a++)<f, ); print1(", "a))
KEYWORD
nonn,more,hard,changed
AUTHOR
Leroy Quet and M. F. Hasler, Mar 14 2008
EXTENSIONS
a(11)-a(13) from Hieronymus Fischer, Jan 06 2009
Edited by R. J. Mathar, May 21 2010
a(14)-a(15) from Robert Price, Mar 12 2019
STATUS
approved
Numbers k such that the fractional part of Pi^k is less than 1/k.
+10
9
1, 3, 5, 9, 10, 11, 59, 81, 264, 281, 472, 3592, 10479, 12128, 65875, 118885
OFFSET
1,2
COMMENTS
Numbers k such that fract(Pi^k) < 1/k, where fract(x) = x-floor(x).
The next such number must be greater than 100000.
a(17) > 300000. - Robert Price, Mar 25 2019
EXAMPLE
a(4) = 9 since fract(Pi^9) = 0.0993... < 1/9, but fract(Pi^k) = 0.3891..., 0.2932..., 0.5310... for 6 <= k <= 8, which all are greater than 1/k.
MATHEMATICA
Select[Range[1000], N[FractionalPart[Pi^#], 100] < (1/#) &] (* G. C. Greubel, Aug 25 2016 *)
PROG
(PARI) isok(k) = frac(Pi^k) < 1/k; \\ Michel Marcus, Feb 11 2014
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 08 2009
EXTENSIONS
a(16) from Robert Price, Mar 25 2019
STATUS
approved
Numbers k such that the fractional part of Pi^k is greater than 1-(1/k).
+10
9
1, 2, 15, 22, 58, 109, 157, 1030, 1071, 1274, 2008, 2322, 5269, 151710
OFFSET
1,2
COMMENTS
Numbers k such that fract(Pi^k) > 1-(1/k), where fract(x) = x-floor(x).
The next such number must be greater than 100000.
a(15) > 300000. - Robert Price, Mar 25 2019
EXAMPLE
a(3) = 15, since fract(Pi^15) = 0.969... > 0.933... = 1 - (1/15), but fract(Pi^k) <= 1 - (1/k) for 3 <= k <= 14.
MATHEMATICA
Select[Range[1000], N[FractionalPart[Pi^#], 100] > 1 - (1/#) &] (* G. C. Greubel, Aug 25 2016 *)
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 06 2009
EXTENSIONS
a(14) from Robert Price, Mar 25 2019
STATUS
approved
Nearest integer to Pi^n.
(Formerly M2841 N1142)
+10
8
1, 3, 10, 31, 97, 306, 961, 3020, 9489, 29809, 93648, 294204, 924269, 2903677, 9122171, 28658146, 90032221, 282844564, 888582403, 2791563950, 8769956796, 27551631843, 86556004192, 271923706894, 854273519914, 2683779414318, 8431341691876, 26487841119104, 83214007069230
OFFSET
0,2
REFERENCES
A. Fletcher, J. C. P. Miller, L. Rosenhead and L. J. Comrie, An Index of Mathematical Tables. Vols. 1 and 2, 2nd ed., Blackwell, Oxford and Addison-Wesley, Reading, MA, 1962, Vol. 1, p. 122.
J. T. Peters, Ten-Place Logarithm Table. Vols. 1 and 2, rev. ed. Ungar, NY, 1957, Vol. 1 (Appendix), p. 1.
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).
EXAMPLE
a(0) = 1 because Pi^0 = 1;
a(2) = 10 because Pi^2 = 9.8696...;
a(10) = 93648 because Pi^10 = 93648.047476...
MAPLE
a := []: Digits := 1000: for n from 0 to 50 do: a := [op(a), round(Pi^n)]: od: seq(a[i+1], i=0..50);
MATHEMATICA
Round[Pi^Range[0, 40]] (* Harvey P. Dale, Jun 10 2024 *)
PROG
(PARI) apply( A002160(n)=Pi^n\/1, [0..50]) \\ An error message will say so if default(realprecision) must be increased. - M. F. Hasler, May 27 2018
CROSSREFS
Cf. A000227 (e^n), A001672 (floor(Pi^n)), A001673 (ceiling(Pi^n)).
KEYWORD
nonn,easy
EXTENSIONS
More terms from Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 29 2003
Edited by M. F. Hasler, May 27 2018
STATUS
approved
Minimal exponents m such that the fractional part of Pi^m obtains a maximum (when starting with m=1).
+10
8
1, 2, 15, 22, 58, 157, 1030, 5269, 145048, 151710
OFFSET
1,2
COMMENTS
Recursive definition: a(1)=1, a(n) = least number m>a(n-1) such that the fractional part of Pi^m is greater than the fractional part of Pi^k for all k, 1<=k<m.
The next such number must be greater than 100000.
a(11) > 300000. - Robert Price, Mar 25 2019
FORMULA
Recursion: a(1):=1, a(k):=min{ m>1 | fract(Pi^m) > fract(Pi^a(k-1))}, where fract(x) = x-floor(x).
EXAMPLE
a(3)=15, since fract(Pi^15)= 0.9693879984..., but fract(Pi^k)<=0.8696... for 1<=k<=14; thus fract(Pi^15)>fract(Pi^k) for 1<=k<15 and 15 is the minimal exponent > 2 with this property.
MATHEMATICA
$MaxExtraPrecision = 100000;
p = 0; Select[Range[1, 10000],
If[FractionalPart[Pi^#] > p, p = FractionalPart[Pi^#]; True] &] (* Robert Price, Mar 25 2019 *)
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 06 2009
EXTENSIONS
a(9)-a(10) from Robert Price, Mar 25 2019
STATUS
approved
Greatest number m such that the fractional part of Pi^A153711(m) >= 1-(1/m).
+10
8
1, 7, 32, 53, 189, 2665, 10810, 26577, 128778, 483367
OFFSET
1,2
FORMULA
a(n) = floor(1/(1-fract(Pi^A153711(n)))), where fract(x) = x-floor(x).
EXAMPLE
a(3) = 32, since 1-(1/33) = 0.9696... > fract(Pi^A153711(3)) = fract(Pi^15) = 0.96938... >= 0.96875 = 1-(1/32).
MATHEMATICA
$MaxExtraPrecision = 100000;
A153711 = {1, 2, 15, 22, 58, 157, 1030, 5269, 145048, 151710};
Floor[1/(1-FractionalPart[Pi^A153711])] (* Robert Price, Apr 18 2019 *)
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 06 2009
EXTENSIONS
a(9)-a(10) from Robert Price, Apr 18 2019
STATUS
approved
Greatest number m such that the fractional part of Pi^A153710(n) <= 1/m.
+10
7
7, 159, 50, 10, 21, 55, 117, 270, 307, 744, 757, 7804, 13876, 62099, 70718, 154755
OFFSET
1,1
FORMULA
a(n) = floor(1/fract(Pi^A153710(n))), where fract(x) = x-floor(x).
EXAMPLE
a(2)=159 since 1/160<fract(Pi^A153710(2))=fract(Pi^3)=0.0062766...<=1/159.
MATHEMATICA
A153710 = {1, 3, 5, 9, 10, 11, 59, 81, 264, 281, 472, 3592, 10479,
12128, 65875, 118885};
Table[fp = FractionalPart[Pi^A153710[[n]]]; m = Floor[1/fp];
While[fp <= 1/m, m++]; m - 1, {n, 1, Length[A153710]}] (* Robert Price, May 10 2019 *)
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 06 2009
EXTENSIONS
a(16) from Robert Price, May 10 2019
STATUS
approved
Greatest number m such that the fractional part of Pi^A153712(n) >= 1-(1/m).
+10
7
1, 7, 32, 53, 189, 131, 2665, 10810, 2693, 1976, 3697, 4289, 26577, 483367
OFFSET
1,2
FORMULA
a(n) = floor(1/(1-fract(Pi^A153712(n)))), where fract(x) = x-floor(x).
EXAMPLE
a(3) = 32, since 1-(1/33) = 0.9696... > fract(Pi^A153712(3)) = fract(Pi^15) = 0.96938... >= 0.96875 = 1-(1/32).
MATHEMATICA
A153712 = {1, 2, 15, 22, 58, 109, 157, 1030, 1071, 1274, 2008, 2322,
5269, 151710};
Table[Floor[1/(1 - FractionalPart[Pi^A153712[[n]]])], {n, 1,
Length[A153712]}] (* Robert Price, May 10 2019 *)
KEYWORD
nonn,more
AUTHOR
Hieronymus Fischer, Jan 06 2009
EXTENSIONS
a(14) from Robert Price, May 10 2019
STATUS
approved

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