A092535 G.f.: (1+x^2)*(1+x^3)/((1-x)*(1-x^2)).

1, 1, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132

Offset: 0

Author

N. J. A. Sloane, Apr 08 2004

Keywords

• nonn
• easy

Links

• G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006.
• Index entries for Molien series
• Index entries for linear recurrences with constant coefficients, signature (2,-1)

Formula

The even numbers >= 4, prefixed by 1, 1, 3.

G.f.: 1+x+3*x^2+(4-2*x)*x^3/(1-x)^2. a(n)=A004278(n), n<>1. [From R. J. Mathar, Dec 15 2008]