A111780 Seventh column (m=6) of unsigned triangle A111595.

1, 42, 1204, 29736, 689850, 15647940, 354718980, 8137289160, 190349674515, 4561677870750, 112317990384600, 2846259737521200, 74306186469414900, 1999421553976446600, 55458660913310655000, 1585528821898619598000

Offset

6,2

Links

Table of n, a(n) for n=6..21.

Formula

E.g.f. (1/sqrt(1-x^2))*((x/(1-x))^6)/6!.

a(n)=(n!/6!)*sum(binomial(2*k, k)*binomial(n-2*k-1, 5)/(4^k), k=0..floor((n-6)/2)), n>=6.

Crossrefs

Sequence in context: A260584 A004373 A001778 * A075922 A230939 A331858

Adjacent sequences: A111777 A111778 A111779 * A111781 A111782 A111783

Keyword

nonn,easy

Author

Wolfdieter Lang, Aug 23 2005

Status

approved