A048515 a(n) = T(n,n), array T given by A048505.

1, 5, 35, 160, 577, 1816, 5245, 14288, 37313, 94384, 232861, 563080, 1339249, 3141464, 7282493, 16711456, 38010625, 85786336, 192282301, 428342936, 948960881, 2091908680, 4590665245, 10032774640, 21843934657

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (9,-33,63,-66,36,-8).

Formula

a(n) = (9*n^2 + n) * 2^(n-2) - n^2 + 1. - Ralf Stephan, Feb 05 2004

G.f.: -(8*x^5-43*x^4+53*x^3-23*x^2+4*x-1) / ((x-1)^3*(2*x-1)^3). - Colin Barker, Feb 25 2015

Prog

(Magma) [(9*n^2 + n) * 2^(n-2) - n^2 + 1: n in [0..30]]; // Vincenzo Librandi, Sep 26 2011
(PARI) Vec(-(8*x^5-43*x^4+53*x^3-23*x^2+4*x-1)/((x-1)^3*(2*x-1)^3) + O(x^100)) \\ Colin Barker, Feb 25 2015

Crossrefs

Sequence in context: A097872 A184707 A124793 * A219973 A100739 A329762

Adjacent sequences: A048512 A048513 A048514 * A048516 A048517 A048518

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved