A126941 The sequence b[n] defined in A126939.

0, 2, 4, 10, 36, 116, 356, 1124, 3558, 11198, 35274, 111208, 350478, 1104474, 3480856, 10970176, 34572858, 108957948, 343386454, 1082198432, 3410598912, 10748664028, 33874922056, 106758413130, 336454174998, 1060351204770, 3341746833612, 10531672766566

Offset

0,2

Comments

Linear recurrence and empirical g.f confirmed for more terms. - Ray Chandler, Mar 07 2024

Links

Ray Chandler, Table of n, a(n) for n = 0..2006

Index entries for linear recurrences with constant coefficients, signature (2, 1, 7, 3, 3, 1).

Formula

Empirical g.f.: 2*(x-1)*x*(x^2+x+1) / (x^6+3*x^5+3*x^4+7*x^3+x^2+2*x-1). - Colin Barker, Apr 08 2013

Mathematica

a[0] = 0; a[1] = 2; a[2] = 4; a[3] = 10; a[4] = 36; a[5] = 116; a[n_] := a[n] = a[n-6] + 3*a[n-5] + 3*a[n-4] + 7*a[n-3] + a[n-2] + 2*a[n-1]; Table[a[n], {n, 0, 27}] (* Jean-François Alcover, Nov 23 2016 *)
LinearRecurrence[{2, 1, 7, 3, 3, 1}, {0, 2, 4, 10, 36, 116}, 28] (* or *)
CoefficientList[ Series[2x (x - 1)(x^2 + x + 1)/(x^6 + 3x^5 + 3x^4 + 7x^3 + x^2 + 2x - 1), {x, 0, 27}], x] (* Robert G. Wilson v, Nov 23 2016 *)

Crossrefs

Sequence in context: A210772 A125859 A103854 * A354963 A188495 A038077

Adjacent sequences: A126938 A126939 A126940 * A126942 A126943 A126944

Keyword

nonn

Author

N. J. A. Sloane, Mar 18 2007

Status

approved