1,1

Table of n, a(n) for n=1..49.

Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

G.f.: x*(4 + x + 2*x^2) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Dec 04 2011

a(n) = -(5/4)*(-1)^(n-1) + 7*(n-1)/2 + 11/4. - Viet Quoc Le Tran, Jun 14 2014

Sequence in context: A188053 A261673 A027708 * A241653 A100107 A066828

Adjacent sequences: A047371 A047372 A047373 * A047375 A047376 A047377

nonn

N. J. A. Sloane

approved