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%I #20 Jun 02 2015 11:39:40
%S 1,2,3,4,15,12,105,24,315,120,3465,40,45045,280,45045,560,765765,5040,
%T 14549535,5040,14549535,55440,334639305,55440,1673196525,720720,
%U 5019589575,720720,145568097675,720720
%N Denominators of alternating sum transform (PSumSIGN) of Harmonic numbers H(n) = A001008/A002805.
%H Robert Israel, <a href="/A035047/b035047.txt">Table of n, a(n) for n = 1..2000</a>
%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F G.f. for A035048(n)/A035047(n) : log(1-x)/(x^2-1). - _Benoit Cloitre_, Jun 15 2003
%F a(n) = denominator((-1)^(n+1)*1/2*(log(2)+(-1)^(n+1)*(gamma+1/2*(psi(1+n/2)-psi(3/2+n/2))+psi(2+n)))), with gamma the Euler-Mascheroni constant. - [_Gerry Martens_, Apr 28 2011]
%p S:= series(log(1-x)/(x^2-1), x, 101):
%p seq(denom(coeff(S,x,j)),j=1..100); # _Robert Israel_, Jun 02 2015
%o (PARI) a(n)=denominator(polcoeff(log(1-x)/(x^2-1)+O(x^(n+1)),n))
%Y Cf. A035048.
%K nonn,frac,easy
%O 1,2
%A _N. J. A. Sloane_.
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