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A145624 Denominator of the polynomial A_l(x) = Sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=8. 2
1, 3, 15, 105, 315, 3465, 45045, 18018, 153153, 14549535, 14549535, 334639305, 1673196525, 5019589575, 145568097675, 18050444111700, 265447707525, 265447707525, 9821565178425, 9821565178425, 57526310330775 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For numerators see A145623. For general properties of A_l(x) see A145609.

LINKS

Robert Israel, Table of n, a(n) for n = 1..1150

FORMULA

Sum_{n >= 1} (A145623(n)/a(n))*x^n = (32*sqrt(x)*log((1+sqrt(x))/(1-sqrt(x))) - 4*log(1-x))/(1-64*x). - Robert Israel, Mar 09 2016

MAPLE

G:= (32*sqrt(x)*ln((1-sqrt(x))/(1+sqrt(x))) + 4*ln(1-x))/(64*x-1):

S:=series(G, x, 101):

seq(denom(coeff(S, x, n)), n=1..100); # Robert Israel, Mar 09 2016

MATHEMATICA

m = 8; aa = {}; Do[k = 0; Do[k = k + m^(2 r + 1 - d)/d, {d, 1, 2 r}]; AppendTo[aa, Denominator[k]], {r, 1, 30}]; aa (* Artur Jasinski, Oct 14 2008 *)

CROSSREFS

Cf. A145609 - A145640.

Sequence in context: A181131 A293996 A229726 * A025547 A220747 A088989

Adjacent sequences:  A145621 A145622 A145623 * A145625 A145626 A145627

KEYWORD

frac,nonn

AUTHOR

Artur Jasinski, Oct 14 2008

EXTENSIONS

Edited by R. J. Mathar, Aug 21 2009

STATUS

approved

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Last modified August 4 06:02 EDT 2021. Contains 346442 sequences. (Running on oeis4.)