A334669 -id:A334669 - cp's OEIS frontend

A275710 Decimal expansion of the Dirichlet eta function at 7.

9, 9, 2, 5, 9, 3, 8, 1, 9, 9, 2, 2, 8, 3, 0, 2, 8, 2, 6, 7, 0, 4, 2, 5, 7, 1, 3, 1, 3, 3, 3, 9, 3, 6, 8, 5, 2, 3, 1, 1, 1, 5, 6, 9, 2, 4, 3, 1, 4, 0, 6, 8, 5, 1, 6, 2, 9, 5, 1, 3, 0, 8, 7, 5, 6, 2, 6, 7, 0, 2, 0, 5, 2, 1, 8, 6, 4, 7, 0, 5, 1, 9, 8, 1, 3, 1, 4, 2, 0, 3, 7, 7, 4, 5, 7, 2, 3, 9, 7, 0

Offset: 0

Terry D. Grant, Aug 06 2016

			0.99259381992283028267...

Cf. A002162 (value at 1), A013665, A072691 (value at 2), A197070 (value at 3), A267315 (value at 4), A267316 (value at 5), A275703 (value at 6), A334668, A334669, A347150, A347059.

RealDigits[63 Zeta[7]/64, 10, 100] [[1]]

-polylog(7, -1) \\ Michel Marcus, Aug 20 2021

s = RLF(0); s
RealField(110)(s)
for i in range(1, 10000): s -= (-1)^i / i^7
print(s) # Terry D. Grant, Aug 06 2016

eta(7) = 63*zeta(7)/64 = (63*A013665)/64.
eta(7) = Lim_{n -> infinity} A334668(n)/A334669(n). - Petros Hadjicostas, May 07 2020
Equals Sum_{k>=1} (-1)^(k+1) / k^7. - Sean A. Irvine, Aug 19 2021

A334668 Numerator of Sum_{k=1..n} (-1)^(k+1)/k^7.

Original entry on oeis.org

1, 127, 277877, 35566069, 2778634972433, 2778624972433, 2288319945032390119, 292904812254103669607, 640582959329009845430509, 640582894792751053318381, 12483149055863937257566687990151, 12483148704882733411491577990151, 783299081298153288298872171970695856067

Offset: 1

Petros Hadjicostas, May 07 2020

Lim_{n -> infinity} a(n)/A334669(n) = A275710 = (63/64)*A013665.

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

Cf. A013665, A275710, A334669 (denominators).

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

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

cp's OEIS Frontend

A275710 Decimal expansion of the Dirichlet eta function at 7.

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