A049609 a(n)=T(n,n+3), array T as in A049600.

0, 1, 7, 43, 253, 1462, 8378, 47818, 272422, 1550927, 8829033, 50276013, 286430763, 1632808572, 9313861092, 53163187748, 303653552188

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Milan Janjic, Two Enumerative Functions

Formula

Conjecture: -(n+3)*(n-1)*a(n) +(7*n^2+8*n-9)*a(n-1) +(-7*n^2+8*n+9)*a(n-2) +(n+1)*(n-3)*a(n-3)=0. - R. J. Mathar, Oct 26 2015

Conjecture: +n*(n+3)*(n-1)*a(n) -(2*n+1)*(3*n^2+3*n-4)*a(n-1) +(n-2)*(n+2)*(n+1)*a(n-2)=0. - R. J. Mathar, Oct 26 2015

Crossrefs

Sequence in context: A125344 A163869 A043553 * A161728 A358682 A271197

Adjacent sequences: A049606 A049607 A049608 * A049610 A049611 A049612

Keyword

nonn

Author

Clark Kimberling

Status

approved