A085280 Expansion of (1-4x+x^2)/((1-x)(1-3x)(1-4x)).

1, 4, 14, 48, 166, 584, 2094, 7648, 28406, 107064, 408574, 1575248, 6123846, 23963944, 94261454, 372262848, 1474702486, 5855763224, 23293912734, 92788230448, 369990660326, 1476475856904, 5895443074414, 23550391238048

Offset

0,2

Comments

Binomial transform of A085279.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Index entries for linear recurrences with constant coefficients, signature (8,-19,12).

Formula

a(n) = 3^n+4^n/3-1/3.

Mathematica

Table[(3^n + 4^n/3 - 1/3), {n, 0, 30}] (* Vincenzo Librandi, May 26 2013 *)
CoefficientList[Series[(1-4x+x^2)/((1-x)(1-3x)(1-4x)), {x, 0, 30}], x] (* Harvey P. Dale, Jan 02 2021 *)

Prog

(Magma) [3^n+4^n/3-1/3: n in [0..30]]; // Vincenzo Librandi, May 26 2013

Crossrefs

Sequence in context: A071753 A071757 A082590 * A007851 A368555 A014325

Adjacent sequences: A085277 A085278 A085279 * A085281 A085282 A085283

Keyword

nonn,easy

Author

Paul Barry, Jun 25 2003

Status

approved