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A134091
Column 1 of triangle A134090.
4
1, 2, 9, 46, 285, 2021, 16023, 139812, 1326111, 13544857, 147880458, 1715413558, 21036674321, 271585117428, 3677831536291, 52081368845176, 769123715337395, 11816582501728389, 188470925178659344, 3114771205613655362
OFFSET
0,2
COMMENTS
Row n of triangle T=A134090 = row n of (I + D*C)^n for n>=0 where C denotes Pascal's triangle, I the identity matrix and D a matrix where D(n+1,n)=1 and zeros elsewhere.
FORMULA
a(n) = [x^n] Sum_{k=0..n+1} C(n+1,k)*x^k/(1-k*x) / [Product_{i=1..k}(1-i*x)].
PROG
(PARI) a(n)=polcoeff(sum(k=0, n+1, binomial(n+1, k)*x^k/(1-k*x)/prod(i=0, k, 1-i*x +x*O(x^n))), n)
CROSSREFS
Cf. A134090; columns: A122455, A134092, A134093; A134094 (row sums); A048993 (S2).
Sequence in context: A161798 A365855 A373312 * A219614 A183166 A032331
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 07 2007
STATUS
approved