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A128493 Denominators of partial sums for a series for (Pi^4)/96. 4
1, 81, 50625, 121550625, 9845600625, 144149438750625, 4117052120156600625, 4117052120156600625, 343860310127599440800625, 44812219476138886724578250625, 44812219476138886724578250625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numerators are given in A120269.

See the comments and the W. Lang link under A120269.

LINKS

Table of n, a(n) for n=1..11.

FORMULA

a(n)=denominator(r(n)) with r(n):=sum(1/(2*k-1)^4,k=1..n).

MATHEMATICA

a[n_] := (Pi^4 - PolyGamma[3, n + 1/2])/96 // Simplify // Denominator; Table[a[n], {n, 1, 11}] (* Jean-Fran├žois Alcover, Dec 05 2013 *)

CROSSREFS

Sequence in context: A189149 A088188 A017560 * A145261 A013745 A093227

Adjacent sequences:  A128490 A128491 A128492 * A128494 A128495 A128496

KEYWORD

nonn,frac,easy

AUTHOR

Wolfdieter Lang Apr 04 2007

STATUS

approved

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Last modified July 16 09:13 EDT 2020. Contains 335784 sequences. (Running on oeis4.)