A130417 Denominator of partial sums for a series of (17/18)*Zeta(4)= (17/1680)*Pi^4.

1, 48, 6480, 725760, 12960000, 2993760000, 13349175840000, 213586813440000, 98036347368960000, 1862690600010240000, 2479241188613629440000, 57022547338113477120000, 125278536501835309232640000, 2556704826568067535360000, 19511694729072094348800000, 183878211126775417143091200000

Offset: 1

Author

Wolfdieter Lang, Jul 13 2007

Keywords

• nonn
• frac
• easy

References

• For the rationals r(n), a reference and a W. Lang link see A130416.

Crossrefs

Numerators are given by A130416.

Programs

PARI

a(n) = denominator(2*sum(k=1, n, 1/((k^4)*binomial(2*k,k)))); \\ Michel Marcus, Nov 09 2019

Formula

a(n) = denominator(r(n)), n >= 1, with r(n) := 2*Sum_{k=1..n} 1/((k^4)*binomial(2*k,k)).

Extensions

More terms from Michel Marcus, Nov 09 2019