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 A111547 #4 Mar 30 2012 18:36:50
%S A111547 1,4,23,165,1383,13083,136863,1562715,19301319,256191363,3636036783,
%T A111547 54956529675,881578601559,14964805041363,268105552191423,
%U A111547 5057384615702235,100224731537223399,2082402995330965923
%N A111547 Column 3 of triangle A111544; also found in column 0 of triangle A111549, which equals the matrix logarithm of A111544.
%F A111547 a(n) = A111544(n+3, 3) = A111549(n+1, 0).
%o A111547 (PARI) {a(n)=if(n<0,0,(matrix(n+4,n+4,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+2)!/2!*x^i)),m-j-1))))^-1)[n+4,4])}
%Y A111547 Cf. A111544, A111549.
%K A111547 nonn
%O A111547 0,2
%A A111547 _Paul D. Hanna_, Aug 07 2005