A109154 - OEIS

%I #3 Mar 30 2012 18:36:49

%S 1,2,4,14,56,262,1348,7574,45616,292442,1978788,14060654,104403304,

%T 807162070,6476169012,53781863598,461194543136,4075567775538,

%U 37048022605956,345883045698222,3311798037556952,32480125869403430

%N Column 1 of triangle A109152.

%C Triangular matrix T=A109152 satisfies: T(n,k) = [T^2](n-1,k) for n>k+1>=1, with T(n,n) = 1 and T(n+1,n) = n+1 for n>=0.

%o (PARI) {a(n)=local(M=matrix(n+2,n+2));M=M^0;for(i=1,n, M=matrix(n+2,n+2,r,c,if(r>=c,if(r==c,1,if(r==c+1,c,(M^2)[r-1,c]))))); return(M[n+2,2])}

%Y Cf. A109152 (triangle), A109153 (column 0), A109155 (column 2), A109156 (row sums).

%K nonn

%O 0,2

%A _Paul D. Hanna_, Jun 20 2005