login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(n) = a(n-1) + 2^(A047258(n)) for n>1, a(1)=1.
1

%I #13 May 22 2013 07:56:10

%S 1,17,49,113,1137,3185,7281,72817,203889,466033,4660337,13048945,

%T 29826161,298261617,835132529,1908874353,19088743537,53448481905,

%U 122167958641,1221679586417,3420702841969,7818749353073,78187493530737

%N a(n) = a(n-1) + 2^(A047258(n)) for n>1, a(1)=1.

%H Vincenzo Librandi, <a href="/A113867/b113867.txt">Table of n, a(n) for n = 1..300</a>

%F G.f.: x*(1+16*x+32*x^2)/((-1+x)*(-1+4*x)*(1+4*x+16*x^2)). - _Vaclav Kotesovec_, Nov 28 2012

%t CoefficientList[Series[(1 + 16 x + 32 x^2) / ((-1 + x) (- 1 + 4 x) (1 + 4 x + 16 x^2)), {x, 0, 30}], x] (* _Vincenzo Librandi_, May 20 2013 *)

%Y Cf. A099974, A112627, A080355, A080567, A099969, A099970, A099971.

%K nonn,easy

%O 1,2

%A _Artur Jasinski_, Jan 27 2006

%E Edited with better definition and offset corrected by _Omar E. Pol_, Jan 08 2009