login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A257045
Denominators of Apéry's rational approximations p_n/q_n to zeta(3).
1
1, 5, 292, 52020, 9504288, 29484180000, 17168660000, 801669704780000, 35930841355360000, 1250077234358967840000, 36426677336311407264000, 11464402743063221545440000, 42860453128110714373355232000
OFFSET
0,2
LINKS
Stéphane Fischler, Irrationalité de valeurs de zêta. Séminaire Bourbaki (2002-2003) Vol. 45, pp. 27-62 [in French]
Eric Weisstein's MathWorld, Apéry's Constant
FORMULA
See Mathematica script.
EXAMPLE
0, 6/5, 351/292, 62531/52020, 11424695/9504288, 35441662103/29484180000, ...
0, 1.2, 1.202..., 1.2020569..., 1.202056903..., 1.20205690316..., ...
MATHEMATICA
p[n_] := Sum[Binomial[n+k, k]^2*Binomial[n, k]^2*(Sum[1/m^3, {m, 1, n}] + Sum[ (-1)^(m-1)/(2*m^3*Binomial[n, m]*Binomial[m+n, m]), {m, 1, k}]), {k, 0, n}]; q[n_] := Sum[Binomial[n+k, k]^2*Binomial[n, k]^2, {k, 0, n}]; Table[p[n]/q[n], {n, 0, 12}] // Denominator
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
STATUS
approved