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A107669
a(n) = A107668(n)/(n+1)^2.
3
1, 1, 5, 51, 809, 17575, 486460, 16384260, 650574249, 29762953831, 1541719486081, 89201504309927, 5702038255950404, 399105271607867940, 30359621863987241460, 2494052823831234355340, 220067051126228849480649
OFFSET
0,3
PROG
(PARI) {a(n)=local(A); if(n==0, n+1, A=(n+1)*x+x*O(x^n); for(k=0, n, A+=polcoeff(A, k)*x^k*(n+1-prod(i=0, k, 1+(i-n-1)*x))); polcoeff(A, n)/(n+1)^2)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jun 07 2005
STATUS
approved