A213556 Principal diagonal of the convolution array A213555.

1, 19, 118, 446, 1271, 3017, 6300, 11964, 21117, 35167, 55858, 85306, 126035, 181013, 253688, 348024, 468537, 620331, 809134, 1041334, 1324015, 1664993, 2072852, 2556980, 3127605, 3795831, 4573674, 5474098, 6511051, 7699501

Offset

1,2

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

Formula

a(n) = (9*n^5 + 15*n^4 + 5*n^3 + n)/30.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6).

G.f.: x*(1 + 13*x + 19*x^2 + 3*x^3)/(1 - x)^6.

Mathematica

(See A213553.)

Crossrefs

Cf. A213553, A213500.

Sequence in context: A041694 A220228 A027460 * A293879 A044351 A044732

Adjacent sequences: A213553 A213554 A213555 * A213557 A213558 A213559

Keyword

nonn,easy

Author

Clark Kimberling, Jun 17 2012

Status

approved