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A213758
Antidiagonal sums of the convolution array A213756.
3
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
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
Sequence in context: A287324 A006414 A344053 * A181960 A219511 A027137
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 20 2012
STATUS
approved