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%I #4 Feb 28 2013 09:27:57
%S 1,3,-13,-10,394,-2016,-5076,170064,-1155024,-5005440,193724640,
%T -1656720000,-10280355840,465087087360,-4804977542400,-39012996556800,
%U 2035558551398400,-24660231399014400,-248246498826547200,14713557956794368000
%N Column 2 of triangle A136590.
%F E.g.f.: A(x) = log(1 + x + x^2)^2 / 2!.
%e E.g.f.: A(x) = 1*x^2/2! + 3*x^3/3! - 13*x^4/4! - 10*x^5/5! + 394*x^6/6! +...
%t With[{nn=30},Drop[CoefficientList[Series[Log[1+x+x^2]^2/2,{x,0,nn}],x] Range[ 0,nn]!,2]] (* _Harvey P. Dale_, Feb 28 2013 *)
%o (PARI) a(n)=(n+2)!*polcoeff(log(1+x+x^2 +x*O(x^(n+2)))^2/2!,n+2)
%Y Cf. A136590, A136591, A136593, A136594.
%K sign
%O 2,2
%A _Paul D. Hanna_, Jan 10 2008
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