A077931 Expansion of 1/((1-x)*(1+2*x+x^2+2*x^3)).

1, -1, 2, -4, 9, -17, 34, -68, 137, -273, 546, -1092, 2185, -4369, 8738, -17476, 34953, -69905, 139810, -279620, 559241, -1118481, 2236962, -4473924, 8947849, -17895697, 35791394, -71582788, 143165577, -286331153, 572662306, -1145324612, 2290649225, -4581298449, 9162596898

Offset

0,3

Links

Table of n, a(n) for n=0..34.

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

Mathematica

CoefficientList[Series[1/((1 - x) * (1 + 2 x + x^2 + 2 x^3)), {x, 0, 50}], x] (* Vladimir Joseph Stephan Orlovsky, Jun 20 2011 *)

Prog

(PARI) Vec(1/((1-x)*(1+2*x+x^2+2*x^3))+O(x^99)) \\ Charles R Greathouse IV, Sep 27 2012

Crossrefs

Sequence in context: A088039 A266108 A360303 * A115451 A245122 A291728

Adjacent sequences: A077928 A077929 A077930 * A077932 A077933 A077934

Keyword

sign,easy

Author

N. J. A. Sloane, Nov 17 2002

Status

approved