This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A136591 #4 Jan 18 2016 21:25:12
%S A136591 1,1,-4,6,24,-240,720,5040,-80640,362880,3628800,-79833600,479001600,
%T A136591 6227020800,-174356582400,1307674368000,20922789888000,
%U A136591 -711374856192000,6402373705728000,121645100408832000,-4865804016353280000,51090942171709440000
%N A136591 Column 1 of triangle A136590.
%F A136591 E.g.f.: log(1 + x + x^2).
%F A136591 a(n) = n!*A061347(n) for n>=1.
%o A136591 (PARI) {a(n) = n!*polcoeff( log(1+x+x^2 +x*O(x^(n+1))),n)}
%o A136591 for(n=1,30,print1(a(n),", "))
%Y A136591 Cf. A136590, A136592, A136593, A136594; A061347.
%K A136591 sign
%O A136591 1,3
%A A136591 _Paul D. Hanna_, Jan 10 2008