A213758 Antidiagonal sums of the convolution array A213756.

1, 9, 40, 130, 355, 871, 1994, 4360, 9245, 19205, 39356, 79934, 161415, 324755, 651870, 1306596, 2616609, 5237265, 10479280, 20964090, 41934571, 83876479, 167761330, 335532160, 671075045, 1342162141, 2684337764, 5368690550

Offset

1,2

Links

Clark Kimberling, Table of n, a(n) for n = 1..100

Index entries for linear recurrences with constant coefficients, signature (6,-14,16,-9,2).

Formula

a(n) = (1/6)*(-120 + 15*2^(n+3) - 81*n - 21*n^2 - 4*n^3).

a(n) = 6*a(n-1) - 14*a(n-2) + 16*a(n-3) - 9*a(n-4) + 2*a(n-5).

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

Mathematica

(See A213756.)

Crossrefs

Cf. A213756, A213500.

Sequence in context: A287324 A006414 A344053 * A181960 A219511 A027137

Adjacent sequences: A213755 A213756 A213757 * A213759 A213760 A213761

Keyword

nonn,easy

Author

Clark Kimberling, Jun 20 2012

Status

approved