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A105625
Row sums of triangle A105623.
0
1, 2, 7, 40, 324, 3336, 41192, 590480, 9623944, 175703056, 3552295752, 78802665120, 1903505233064, 49743146641616, 1398474578414632, 42092742475096960, 1350629892258170184, 46025643554111478576
OFFSET
0,2
COMMENTS
A105623 equals the matrix square-root of triangle A105615.
PROG
(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])))}
CROSSREFS
Sequence in context: A162653 A346220 A166904 * A367255 A135082 A372348
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 16 2005
STATUS
approved