login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Column 1 of triangle A132875.
4

%I #2 Mar 31 2012 20:25:45

%S 1,6,72,2240,157200,20017032,3986643136,1133413590528,433294691800320,

%T 213579235442893760,131576955596091312384,98894873879740831706112,

%U 88957131079138422705160192,94267354032238753666544536320

%N Column 1 of triangle A132875.

%C Triangle T=A132875 obeys: the g.f. of row n of T^n = (y + n*(n+1))^n for n>=0.

%F a(n)/[(n+1)*(n+2)/2] = A132879(n) for n>=0.

%o (PARI) {a(n)=local(M=Mat([1,0;1,1]),N,L);for(i=1,n,N=M; M=matrix(#N+1,#N+1,r,c,if(r>=c,if(r<=#N,(N^(#N))[r,c], polcoeff((x+(#M)*(#M+1))^(#M),c-1)))); L=sum(i=1,#M,-(M^0-M)^i/i);M=sum(i=0,#M,(L/#N)^i/i!);); M[n+2,2]}

%Y Cf. A132875, A132876, A132877, A132879.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Sep 29 2007