

A109156


Row sums of triangle A109152.


4



1, 2, 5, 14, 47, 188, 867, 4460, 25025, 150890, 967825, 6554482, 46600855, 346228012, 2677951311, 21495038944, 178565654041, 1531692226714, 13538763090277, 123096619532030, 1149440819867767, 11007471611129700
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OFFSET

0,2


COMMENTS

Triangular matrix T=A109152 satisfies: T(n,k) = [T^2](n1,k) for n>k+1>=1, with T(n,n) = 1 and T(n+1,n) = n+1 for n>=0.


LINKS



PROG

(PARI) {a(n)=local(M=matrix(n+1, n+1)); M=M^0; for(i=1, n, M=matrix(n+1, n+1, r, c, if(r>=c, if(r==c, 1, if(r==c+1, c, (M^2)[r1, c]))))); return(sum(k=0, n, M[n+1, k+1]))}


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



