A025260 - OEIS

A025260

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

2, -2, 1, 2, 2, 1, 2, 10, 26, 44, 68, 149, 398, 938, 1918, 3916, 8892, 21258, 49028, 108580, 242132, 558456, 1306824, 3026445, 6938518, 15984346, 37243510, 87188492, 203625452, 474753470, 1110012828, 2606486124, 6132979116, 14430908200, 33968899384

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..35.

FORMULA

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

CROSSREFS

Sequence in context: A124800 A247349 A069163 * A227156 A123369 A178306

Adjacent sequences: A025257 A025258 A025259 * A025261 A025262 A025263

KEYWORD

sign

AUTHOR

Clark Kimberling

STATUS

approved