A126943 The sequence d[n] defined in A126939.

0, 0, 4, 14, 36, 116, 378, 1178, 3700, 11694, 36852, 116082, 365886, 1153178, 3634154, 11453184, 36095524, 113756584, 358508862, 1129858168, 3560801564, 11222032838, 35366766278, 111460034016, 351271552234, 1107048863804, 3488916716866, 10995485596894

Offset

0,3

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^2*(x+1)*(x^2+x+2) / (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] = 0; a[2] = 4; a[3] = 14; 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, 0, 4, 14, 36, 116}, 28] (* or *)
CoefficientList[ Series[-2x^2*(x + 1)*(x^2 + x + 2)/(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: A258343 A317148 A027166 * A209399 A192974 A187428

Adjacent sequences: A126940 A126941 A126942 * A126944 A126945 A126946

Keyword

nonn

Author

N. J. A. Sloane, Mar 18 2007

Status

approved