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 A112693 #9 Jul 10 2013 16:26:58 %S A112693 1,-4,-48,2304,552960,-796262400,-8026324992000,647242847354880000, %T A112693 469742968896277708800000,-3409206571061625099386880000000, %U A112693 -272169233711505353534412423168000000000 %N A112693 Row sums of array A112692. %F A112693 a(n)=sum(A112692(k, m), m=0..((k+1)*(k+2)/2)-1), k>=0. %F A112693 Let A(x)=sum(k>=0, |a(k)|*x^k ), then A(x)= G(0)/(4*x)- 1/(2*x), where G(k)= 1 + 1/(1 - 2*x*(2*k+1)!/(2*x*(2*k+1)! + 1/(1 + 1/(1 - 2*x*(2*k+2)!/(2*x*(2*k+2)! + 1/G(k+1) ))))); (continued fraction). - _Sergei N. Gladkovskii_, Jul 10 2013 %Y A112693 Unsigned row sums A112694. %K A112693 sign,easy %O A112693 0,2 %A A112693 _Wolfdieter Lang_, Oct 14 2005