A083319 4^n+3^n-2^n.

1, 5, 21, 83, 321, 1235, 4761, 18443, 71841, 281315, 1106601, 4369403, 17304561, 68694995, 273202041, 1088057963, 4337948481, 17308878275, 69106635081, 276039644123, 1102997363601, 4408504767155, 17623562909721, 70462878967883

Offset: 0

Author

Paul Barry, Apr 25 2003

Keywords

• easy
• nonn

Comments

Binomial transform of A083318

Links

• Index entries for linear recurrences with constant coefficients, signature (9,-26,24).

Crossrefs

Cf. A083320.

Programs

Mathematica

CoefficientList[Series[(1-4x+2x^2)/((1-2x)(1-3x)(1-4x)), {x,0,40}],x]  (* Harvey P. Dale, Mar 28 2011 *)

Formula

a(n)=4^n+3^n-2^n.

G.f. (1-4x+2x^2)/((1-2x)(1-3x)(1-4x)).

E.g.f. exp(4x)+exp(3x)-exp(2x)