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 A105625 #3 Mar 30 2012 18:36:45 %S A105625 1,2,7,40,324,3336,41192,590480,9623944,175703056,3552295752, %T A105625 78802665120,1903505233064,49743146641616,1398474578414632, %U A105625 42092742475096960,1350629892258170184,46025643554111478576 %N A105625 Row sums of triangle A105623. %C A105625 A105623 equals the matrix square-root of triangle A105615. %o A105625 (PARI) {a(n)=local(R,M=matrix(n+3,n+3,m,j,if(m>=j,if(m==j,1,if(m==j+1,-2*j, polcoeff(1/sum(i=0,m-j,(2*i)!/i!/2^i*x^i)+O(x^m),m-j)))))^-1); R=(M+M^0)/2;for(i=1,floor(2*log(n+2)),R=(R+M*R^(-1))/2); return(if(n<0,0,sum(k=0,n,R[n+1,k+1])))} %Y A105625 Cf. A105615, A105623. %K A105625 nonn %O A105625 0,2 %A A105625 _Paul D. Hanna_, Apr 16 2005