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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.
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%I #13 Jul 04 2017 14:37:03

%S 1,3,15,105,315,3465,45045,18018,153153,14549535,14549535,334639305,

%T 1673196525,5019589575,145568097675,18050444111700,265447707525,

%U 265447707525,9821565178425,9821565178425,57526310330775

%N 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.

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

%H Robert Israel, <a href="/A145624/b145624.txt">Table of n, a(n) for n = 1..1150</a>

%F 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

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

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

%p seq(denom(coeff(S,x,n)),n=1..100); # _Robert Israel_, Mar 09 2016

%t 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 *)

%Y Cf. A145609 - A145640.

%K frac,nonn

%O 1,2

%A _Artur Jasinski_, Oct 14 2008

%E Edited by _R. J. Mathar_, Aug 21 2009