A334604 Denominator of Sum_{k=1..n} (-1)^(k+1)/k^5.

1, 32, 7776, 248832, 777600000, 777600000, 13069123200000, 418211942400000, 101625502003200000, 101625502003200000, 16366888723117363200000, 16366888723117363200000, 6076911214672415134617600000

Offset: 1

Author

Petros Hadjicostas, May 07 2020

Keywords

• nonn

Comments

Lim_{n -> infinity} A136676(n)/a(n) = A267316 = (15/16)*A013663.

Examples

			The first few fractions are 1, 31/32, 7565/7776, 241837/248832, 755989457/777600000, 755889457/777600000, ... = A136676/A334604.
		

Crossrefs

Cf. A013663, A136676 (numerators), A267316.

Programs

Mathematica

Denominator @ Accumulate[Table[(-1)^(k + 1)/k^5, {k, 1, 13}]] (* Amiram Eldar, May 08 2020 *)

PARI

a(n) = denominator(sum(k=1, n, (-1)^(k+1)/k^5)); \\ Michel Marcus, May 07 2020