A134270 a(n)=2a(n-1)+a(n-2)-4a(n-4).

1, 1, 3, 7, 13, 29, 59, 119, 245, 493, 995, 2007, 4029, 8093, 16235, 32535, 65189, 130541, 261331, 523063, 1046701, 2094301, 4189979, 8382007, 16767189, 33539181, 67085635, 134182423, 268381725, 536789149, 1073617483, 2147294423, 4294679429, 8589496685

Offset: 0

Author

Paul Curtz, Jan 30 2008

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (2, 1, 0, -4).

Programs

Mathematica

LinearRecurrence[{2,1,0,-4},{1,1,3,7},40] (* Harvey P. Dale, Jan 16 2013 *)

Formula

O.g.f.: (1+x)*x/(2*x^3+x^2-1)-1/(2*x-1) . a(n) = -|A078028(n-1)| + 2^n . - R. J. Mathar, Feb 01 2008

Extensions

More terms from Harvey P. Dale, Jan 16 2013