A174565 Expansion of g.f. (1+3*x)/((1-x)*(1+3*x+4*x^2)).

1, 1, -3, 9, -11, 1, 45, -135, 229, -143, -483, 2025, -4139, 4321, 3597, -28071, 69829, -97199, 12285, 351945, -1104971, 1907137, -1301523, -3723975, 16378021, -34238159, 37202397, 25345449, -224845931, 573156001, -820084275, 167628825, 2777450629, -9002867183

Offset

0,3

Comments

Bisection of A107443.

Links

Table of n, a(n) for n=0..33.

Index entries for linear recurrences with constant coefficients, signature (-2, -1, 4).

Formula

a(n) = (1/2)*(1 - A087168(n+1)).

Prog

(Magma) a087168:=func< n | &+[ Binomial(n+k, 2*k)*(-2)^(n-k): k in [0..n] ] >; [ (1-a087168(n+1))/2: n in [0..35] ];

Crossrefs

Sequence in context: A121057 A025538 A070354 * A074261 A059868 A101735

Adjacent sequences: A174562 A174563 A174564 * A174566 A174567 A174568

Keyword

sign,easy

Author

Ralf Stephan, Nov 29 2010

Status

approved