A200862 G.f.: (1-2*x^2)/(1-2*x-5*x^2+9*x^3).

1, 2, 7, 15, 47, 106, 312, 731, 2068, 4983, 13727, 33757, 91302, 227846, 608389, 1534290, 4059911, 10315771, 27122487, 69284630, 181339756, 465000279, 1213137668, 3119218927, 8119123683, 20916102989, 54354854050, 140218109898, 363965563145, 939827989330, 2437520805303, 6298491488951, 16326135100447

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Peter Lawrence et al., sequence challenge and follow-up messages on the SeqFan list, Nov 21 2011

Index entries for linear recurrences with constant coefficients, signature (2,5,-9).

Formula

a(n) = 2*a(n-1) +5*a(n-2) -9*a(n-3) for n>2. - Vincenzo Librandi, Jun 30 2014

Mathematica

LinearRecurrence[{2, 5, -9}, {1, 2, 7}, 40] (* Harvey P. Dale, Jun 29 2014 *)
CoefficientList[Series[(1 - 2 x^2)/(1 - 2 x - 5 x^2 + 9 x^3), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 30 2014 *)

Crossrefs

Sequence in context: A330454 A121165 A093652 * A096690 A279286 A282197

Adjacent sequences: A200859 A200860 A200861 * A200863 A200864 A200865

Keyword

nonn

Author

N. J. A. Sloane, Nov 23 2011

Status

approved