A116871 Sixth column of triangle A067323.

42, 174, 645, 2333, 8398, 30275, 109550, 398180, 1453908, 5332407, 19639521, 72616727, 269473750, 1003347975, 3747412770, 14036374680, 52714429260, 198459284400, 748867149234, 2831788492218, 10729442739596

Offset

0,1

Comments

Also sixth diagonal sequence of triangle A028364.

Links

Table of n, a(n) for n=0..20.

Formula

a(n)= A067323(n+5,5), n>=0.

a(n)= A028364(5+n,n) = sum(C(k)*C(5+n-k),k=0..n), n>=0, with the Catalan numbers C(n):=A000108(n).

G.f.: (c(x)^3)sum(C(4, k)*c(x)^k, k=0..4), with C(n, m) := (m+1)*binomial(2*n-m, n-m)/(n+1) (Catalan convolutions A033184).

Crossrefs

Cf. A067326 (fifth column of A067323).

Sequence in context: A134385 A232329 A115130 * A158484 A154047 A090198

Adjacent sequences: A116868 A116869 A116870 * A116872 A116873 A116874

Keyword

nonn,easy

Author

Wolfdieter Lang, Mar 24 2006

Status

approved