login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A136169 a(n) = 2*a(n-1) - [(n+1)/3] for n>0 with a(0) = 1. 1

%I

%S 1,2,3,5,9,16,30,58,113,223,443,882,1760,3516,7027,14049,28093,56180,

%T 112354,224702,449397,898787,1797567,3595126,7190244,14380480,

%U 28760951,57521893,115043777,230087544,460175078,920350146,1840700281,3681400551

%N a(n) = 2*a(n-1) - [(n+1)/3] for n>0 with a(0) = 1.

%F G.f. A(x) = (1 - x^2*(1+x+x^2)/(1-x^3)^2 )/(1-2*x).

%o (PARI) {a(n)=if(n==0,1,2*a(n-1)-((n+1)\3))}

%Y Cf. A136219.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Dec 23 2007

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 11 11:54 EDT 2021. Contains 343791 sequences. (Running on oeis4.)