A214092 Principal diagonal of the convolution array A213773.

1, 23, 102, 274, 575, 1041, 1708, 2612, 3789, 5275, 7106, 9318, 11947, 15029, 18600, 22696, 27353, 32607, 38494, 45050, 52311, 60313, 69092, 78684, 89125, 100451, 112698, 125902, 140099, 155325, 171616

Offset: 1

Author

Clark Kimberling, Jul 04 2012

Keywords

• nonn
• easy

Links

• Clark Kimberling, Table of n, a(n) for n = 1..999
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Crossrefs

Cf. A213773.

Cf. A260260 (comment). [Bruno Berselli, Jul 22 2015]

Programs

Mathematica

(See A213773.)
LinearRecurrence[{4,-6,4,-1},{1,23,102,274},40] (* Harvey P. Dale, Nov 20 2015 *)

Formula

a(n) = (5*n - 15*n^2 + 12*n^3)/2.

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).

G.f.: f(x)/g(x), where f(x) = x*(1 + 19*x + 16*x^2) and g(x) = (1-x)^4.