A256323 a(n) = numerator of (1/n^3)*(-1/(n+1) + 16/(n+2) + 3/(4*(2*n+1)) - 81/(4*(2*n+3))), term of a BBP-type series representation of zeta(3) by V. Adamchik and S. Wagon.

31, 97, 113, 39, 3781, 257, 3131, 6791, 6287, 2113, 33193, 787, 5933, 2063, 26827, 16153, 115453, 11351, 53107, 92453, 23677, 3389, 277777, 52421, 118127, 99367, 147971, 82307, 547381, 4199, 24659, 365459, 266719, 72803, 951481, 172303, 373591

Offset

1,1

Links

Table of n, a(n) for n=1..37.

Victor Adamchik and Stan Wagon, Pi: A 2000-Year Search Changes Direction

David Bailey, Peter Borwein, Simon Plouffe, On the rapid computation of various polylogarithmic constants

Eric Weisstein's MathWorld, BBP-Type Formula

Wikipedia, Bailey-Borwein-Plouffe formula

Formula

a(n) = Numerator(1/n^3+1/(n+1)-2/(n+2)-6/(2*n+1)+6/(2*n+3)+1/n). - Peter Luschny, Mar 24 2015

Maple

a := n -> numer(1/n^3+1/(n+1)-2/(n+2)-6/(2*n+1)+6/(2*n+3)+1/n):
seq(a(n), n=1..37); # Peter Luschny, Mar 24 2015

Mathematica

a[n_] := Numerator[(1/n^3)*(-1/(n+1) + 16/(n+2) + 3/(4*(2*n+1)) - 81/(4*(2*n+3)))]; Table[a[n], {n, 1, 40}]

Prog

(Magma) [Numerator((1/n^3)*(-1/(n+1)+16/(n+2)+3/(4*(2*n+1))-81/(4*(2*n+3)))): n in [1..40]]; // Vincenzo Librandi, Mar 24 2015

Crossrefs

Cf. A002117, A256324 (denominators).

Sequence in context: A044599 A143032 A159014 * A142067 A081275 A139509

Adjacent sequences: A256320 A256321 A256322 * A256324 A256325 A256326

Keyword

nonn,frac,easy

Author

Jean-François Alcover, Mar 24 2015

Status

approved