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 A009344 #19 Apr 01 2017 14:05:00
%S A009344 0,2,-20,512,-27680,2565632,-363299840,72957489152,-19722824192000,
%T A009344 6905862783107072,-3040352844189532160,1643816046204280635392,
%U A009344 -1070739118373698870968320,827017799903621162951770112
%N A009344 Expansion of log(1 + sin(x)^2).
%F A009344 a(n) ~ (2*n)! * (-1)^(n+1) / (n * log(1+sqrt(2))^(2*n)). - _Vaclav Kotesovec_, Jan 23 2015
%t A009344 Log[ 1+Sin[ x ]^2 ] (* Even Part *)
%t A009344 nn = 20; Table[(CoefficientList[Series[Log[1 + Sin[x]^2], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* _Vaclav Kotesovec_, Jan 23 2015 *)
%o A009344 (Maxima) b(n):=sum(((-1)^(k-1)*((-1)^(n-2*k)+1)*sum((2*i-2*k)^n*binomial(2*k,i)*(-1)^((n+2*k)/2-i),i,0,k))/(k*2^(2*k)),k,1,n/2);
%o A009344 a(n)=b(2*n); /* _Vladimir Kruchinin_, Jun 28 2011 */
%K A009344 sign
%O A009344 0,2
%A A009344 _R. H. Hardin_
%E A009344 Extended with signs by _Olivier Gérard_, Mar 15 1997