A113867 a(n) = a(n-1) + 2^(A047258(n)) for n>1, a(1)=1.

1, 17, 49, 113, 1137, 3185, 7281, 72817, 203889, 466033, 4660337, 13048945, 29826161, 298261617, 835132529, 1908874353, 19088743537, 53448481905, 122167958641, 1221679586417, 3420702841969, 7818749353073, 78187493530737

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..300

Formula

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

Mathematica

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 *)

Crossrefs

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

Sequence in context: A069129 A176273 A124710 * A049737 A146871 A146791

Adjacent sequences: A113864 A113865 A113866 * A113868 A113869 A113870

Keyword

nonn,easy

Author

Artur Jasinski, Jan 27 2006

Extensions

Edited with better definition and offset corrected by Omar E. Pol, Jan 08 2009

Status

approved