login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A174836 a(n) = 1 + ((6*n-1)*2^n + (-1)^n)/3. 0

%I

%S 1,4,16,46,124,310,748,1750,4012,9046,20140,44374,96940,210262,453292,

%T 972118,2075308,4412758,9349804,19748182,41593516,87381334,183151276,

%U 383079766,799713964,1666536790,3467291308,7203018070,14942907052,30959555926,64066595500,132428158294

%N a(n) = 1 + ((6*n-1)*2^n + (-1)^n)/3.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4, -3, -4, 4).

%F G.f.: 1/(1-x) + 1/(3*(1+x)) - 1/(3*(1-2*x)) + 8*x/(1-2*x)^2. [_Richard Choulet_, Apr 04 2010]

%F a(n) = 3*A113861(n+1) + 1. - _Michel Marcus_, Feb 05 2019

%o (PARI) a(n) = 1 + ((6*n-1)*2^n+(-1)^n)/3; \\ _Michel Marcus_, Feb 05 2019

%Y Cf. A113861.

%K nonn,easy

%O 0,2

%A Fernando J. Ballesteros (fernando.ballesteros(AT)uv.es), Mar 30 2010

%E More terms from _Michel Marcus_, Feb 05 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 7 14:56 EDT 2022. Contains 355989 sequences. (Running on oeis4.)