A016200 Expansion of 1/((1-x)(1-2x)(1-6x)).

1, 9, 61, 381, 2317, 13965, 83917, 503757, 3023053, 18139341, 108838093, 653032653, 3918204109, 23509241037, 141055478989, 846332939469, 5077997767885, 30467986869453, 182807921741005, 1096847531494605

Offset

0,2

Links

Muniru A Asiru, Table of n, a(n) for n = 0..250

Index entries for linear recurrences with constant coefficients, signature (9,-20,12).

Formula

a(n) = (9*6^n - 5*2^n + 1)/5. - Bruno Berselli, Feb 09 2011

a(0)=1, a(n) = 6*a(n-1) + 2^(n+1) - 1. - Vincenzo Librandi, Feb 09 2011

a(n) = Sum_{k=0..n} 2^(n-1-k) * (3^(n+1-k) - 1). - J. M. Bergot, Feb 06 2018

Maple

seq((9*6^n-5*2^n+1)/5, n=0..100); # Muniru A Asiru, Feb 06 2018

Prog

(GAP) List([0..100], n->(9*6^n-5*2^n+1)/5); # Muniru A Asiru, Feb 06 2018

Crossrefs

Sequence in context: A005060 A125346 A190666 * A001454 A243877 A200674

Adjacent sequences: A016197 A016198 A016199 * A016201 A016202 A016203

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved