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A213830
Antidiagonal sums of the convolution array A213828.
3
2, 18, 78, 230, 540, 1092, 1988, 3348, 5310, 8030, 11682, 16458, 22568, 30240, 39720, 51272, 65178, 81738, 101270, 124110, 150612, 181148, 216108, 255900, 300950, 351702, 408618, 472178, 542880, 621240
OFFSET
1,1
COMMENTS
Every term is even.
FORMULA
a(n) = (2*n + n^2 + 2*n^3 + 3*n^4)/4.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5).
G.f.: f(x)/g(x), where f(x) = 2*x*(1 + 4*x + 4*x^2) and g(x) = (1-x)^5.
MATHEMATICA
(See A213828.)
LinearRecurrence[{5, -10, 10, -5, 1}, {2, 18, 78, 230, 540}, 30] (* Harvey P. Dale, Jan 11 2015 *)
CROSSREFS
Cf. A213828.
Sequence in context: A034473 A024171 A056664 * A323947 A064057 A176496
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jul 04 2012
STATUS
approved