A213754 Principal diagonal of the convolution array A213753.

1, 16, 111, 576, 2631, 11292, 46927, 191680, 775599, 3122076, 12531591, 50220912, 201088855, 804798268, 3220143903, 12882607872, 51534757599, 206148206268, 824612224663, 3298489794160, 13194045161031, 52776361000476

Offset: 1

Author

Clark Kimberling, Jun 20 2012

Keywords

• nonn
• easy

Links

• Clark Kimberling, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (11,-47,101,-116,68,-16).

Crossrefs

Cf. A213753, A213500.

Programs

Mathematica

(See A213753.)

PARI

Vec(x*(1 + 5*x - 18*x^2 + 6*x^3 + 12*x^4) / ((1 - x)^3*(1 - 2*x)^2*(1 - 4*x)) + O(x^30)) \\ Colin Barker, Nov 07 2017

Formula

a(n) = -3*2^n + 3*2^(2*n) - n*2^(n+1) - n^2.

a(n) = 11*a(n-1) - 47*a(n-2) + 101*a(n-3) - 116*a(n-4) + 68*a(n-5) - 16*a(n-6) for n>5. Corrected by Colin Barker, Nov 07 2017

G.f.: f(x)/g(x), where f(x) = x*(1 + 5*x - 18*x^2 + 6*x^3 + 12*x^4) and g(x) = (1 - 4*x) * (1 - x)^3 * (1 - 2*x)^2.