A155701 a(n) = (4^n + 8)/3.

3, 4, 8, 24, 88, 344, 1368, 5464, 21848, 87384, 349528, 1398104, 5592408, 22369624, 89478488, 357913944, 1431655768, 5726623064, 22906492248, 91625968984, 366503875928, 1466015503704, 5864062014808, 23456248059224, 93824992236888, 375299968947544

Offset: 0

Author

Paul Curtz, Jan 25 2009

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (5,-4).

Programs

Magma

[(4^n+8)/3: n in [0..35]]; // Vincenzo Librandi, Jul 24 2011

Maple

A155701 := proc(n) (4^n+8)/3 ; end: seq(A155701(n),n=0..80) ; # R. J. Mathar, Jul 23 2009

Mathematica

A155701[n_]:=(4^n+8)/3;Array[A155701,50,0] (* Paolo Xausa, Dec 05 2023 *)

Formula

a(n) = 3 + A002450(n).

a(n) = 5*a(n-1) - 4*a(n-2) = 4*a(n-1) - 8.

a(n) = A154879(2n) = A154890(2n).

a(n+1) - a(n) = A000302(n).

a(n+1) = 4*A047849(n) = 4*A078008(2n).

G.f.: (3-11*x)/((4*x-1)*(x-1)). - R. J. Mathar, Jul 23 2009

Extensions

Edited and extended by R. J. Mathar, Jul 23 2009