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A176448 7*2^n-2 2
5, 12, 26, 54, 110, 222, 446, 894, 1790, 3582, 7166, 14334, 28670, 57342, 114686, 229374, 458750, 917502, 1835006, 3670014, 7340030, 14680062, 29360126, 58720254, 117440510, 234881022, 469762046, 939524094, 1879048190, 3758096382 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

a(n)=2*A086224(n-1) n>0; (Berselli - Librandi) [From Vincenzo Librandi, Aug 27 2010]

LINKS

Table of n, a(n) for n=0..29.

Index entries for linear recurrences with constant coefficients, signature (3,-2).

FORMULA

a(n)=2*(a(n-1)+1) with a(0)=5

a(n)= +3*a(n-1) -2*a(n-2). G.f.: ( 5-3*x ) / ( (2*x-1)*(x-1) ). [From R. J. Mathar, May 02 2010]

a(n) = A174317(n+3). - R. J. Mathar, Feb 21 2016

EXAMPLE

For n=1, a(1)=2*(5+1)=12; n=2, a(2)=2*(12+1)=26; n=3, a(3)=2*(26+1)=54

MATHEMATICA

Table[7*2^n-2, {n, 0, 30}] (* or *) LinearRecurrence[{3, -2}, {5, 12}, 30] (* Harvey P. Dale, May 21 2017 *)

PROG

(MAGMA) [7*2^n-2: n in [0..100]]

CROSSREFS

Sequence in context: A212561 A199771 A200252 * A078517 A170828 A229422

Adjacent sequences:  A176445 A176446 A176447 * A176449 A176450 A176451

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Apr 18 2010

STATUS

approved

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Last modified June 20 16:07 EDT 2021. Contains 345166 sequences. (Running on oeis4.)