A206372 a(n) = 14 * 4^n - 1.

13, 55, 223, 895, 3583, 14335, 57343, 229375, 917503, 3670015, 14680063, 58720255, 234881023, 939524095, 3758096383, 15032385535, 60129542143, 240518168575, 962072674303, 3848290697215, 15393162788863, 61572651155455, 246290604621823, 985162418487295

Offset

0,1

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5, -4).

Formula

a(n) = 7*2^(2*n+1) - 1.

a(n) = (A199207(n+1) -3)/2 for n>=0.

From G. C. Greubel, Jan 05 2023: (Start)

a(n) = A005009(2*n+1) - 1.

G.f.: (13 - 10*x)/((1-x)*(1-4*x)).

E.g.f.: 14*exp(4*x) - exp(x). (End)

Mathematica

7*2^(2*Range[0, 50]+1)-1 (* G. C. Greubel, Jan 05 2023 *)

Prog

(Magma) [14*4^n-1 : n in [0..30]];
(PARI) a(n)=14*4^n - 1 \\ Charles R Greathouse IV, May 05 2014
(SageMath) [7*2^(2*n+1)-1 for n in range(51)] # G. C. Greubel, Jan 05 2023

Crossrefs

Cf. A005009, A199207.

Sequence in context: A274973 A005902 A051798 * A290396 A061161 A212053

Adjacent sequences: A206369 A206370 A206371 * A206373 A206374 A206375

Keyword

nonn,easy

Author

Brad Clardy, Feb 07 2012

Status

approved