A067299 Second column of triangle A067298.

2, 5, 32, 284, 2960, 33872, 411776, 5221568, 68299520, 914858240, 12486496256, 173031701504, 2428066058240, 34432752275456, 492697174507520, 7104716644990976, 103142445617709056, 1506248913346691072

Offset

0,1

Links

Table of n, a(n) for n=0..17.

Formula

a(n)=A067298(n+1, 1).

G.f.: ((1+x)*c(2, 2; x)-1)/x, with c(2, 2; x) := (1-3*x*c(4*x))/(1-2*x*c(4*x))^2 g.f. for A064340 and c(x) is g.f. for A000108 (Catalan).

G.f.: (2+x + 12*x*(1+x)*c(4*x))/(1+2*x)^2, where c(x) is g.f. for A000108 (Catalan). - Wolfdieter Lang, May 05 2006.

Conjecture: n*(17*n-7)*a(n) +2*(-119*n^2+270*n-96)*a(n-1) -16*(17*n+10)*(2*n-3)*a(n-2)=0. - R. J. Mathar, Jul 21 2016

Crossrefs

Cf. A064340 (first column), A067300 (third column).

Sequence in context: A009274 A019036 A005636 * A353195 A203227 A207135

Adjacent sequences: A067296 A067297 A067298 * A067300 A067301 A067302

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 05 2002

Status

approved