A334669 Denominator of Sum_{k=1..n} (-1)^(k+1)/k^7.

1, 128, 279936, 35831808, 2799360000000, 2799360000000, 2305393332480000000, 295090346557440000000, 645362587921121280000000, 645362587921121280000000, 12576291107821424895098880000000, 12576291107821424895098880000000, 789143616376081512994335288360960000000

Offset: 1

Author

Petros Hadjicostas, May 07 2020

Keywords

• nonn
• frac

Comments

Lim_{n -> infinity} A334668(n)/a(n) = A275710 = (63/64)*A013665.

Examples

			The first few fractions are 1, 127/128, 277877/279936, 35566069/35831808, 2778634972433/2799360000000, 2778624972433/2799360000000, ... = A334668/A334669.
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..336

Crossrefs

Cf. A013665, A275710, A334668 (numerators).

Programs

Mathematica

Denominator @ Accumulate[Table[(-1)^(k + 1)/k^7, {k, 1, 13}]] (* Amiram Eldar, May 08 2020 *)

PARI

a(n) = denominator(sum(k=1, n, (-1)^(k+1)/k^7)); \\ Michel Marcus, May 08 2020