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URL: https://oeis.org/A155701

⇱ A155701 - OEIS

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A155701
a(n) = (4^n + 8)/3.
4
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
0,1
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
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 *)
PROG
(Magma) [(4^n+8)/3: n in [0..35]]; // Vincenzo Librandi, Jul 24 2011
CROSSREFS
Sequence in context: A374311 A217248 A168382 * A353950 A119529 A366812
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jan 25 2009
EXTENSIONS
Edited and extended by R. J. Mathar, Jul 23 2009
STATUS
approved