A025261 a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-3)*a(3) for n >= 4.

3, -2, 1, 3, 7, 16, 40, 111, 327, 984, 2984, 9120, 28156, 87830, 276442, 876443, 2795523, 8963668, 28877692, 93433104, 303474772, 989159058, 3234373630, 10606540108, 34874855416, 114951540690, 379751773694, 1257173264286, 4170000218994

Offset

1,1

Links

Table of n, a(n) for n=1..29.

Formula

Conjecture: n*a(n) +3*(-2*n+3)*a(n-1) +13*(n-3)*a(n-2) +8*(-2*n+9)*a(n-3) +4*(n-6)*a(n-4)=0. - R. J. Mathar, Feb 25 2015

Crossrefs

Sequence in context: A124782 A106611 A331523 * A111572 A046900 A365367

Adjacent sequences: A025258 A025259 A025260 * A025262 A025263 A025264

Keyword

sign

Author

Clark Kimberling

Status

approved