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A213780
Antidiagonal sums of the convolution array A213778.
3
1, 6, 17, 40, 78, 140, 230, 360, 535, 770, 1071, 1456, 1932, 2520, 3228, 4080, 5085, 6270, 7645, 9240, 11066, 13156, 15522, 18200, 21203, 24570, 28315, 32480, 37080, 42160, 47736, 53856, 60537, 67830, 75753, 84360, 93670, 103740, 114590
OFFSET
1,2
FORMULA
a(n) = 3*a(n-1) - a(n-2) - 5*a(n-3) + 5*a(n-4) + a(n-5) - 3*a(n-6) + a(n-7).
G.f.: f(x)/g(x), where f(x) = x*(1 + 3*x) and g(x) = (1 + x)^2 *(1 - x)^5.
MATHEMATICA
(See A213778.)
CROSSREFS
Sequence in context: A366104 A080275 A061349 * A101945 A220407 A013319
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 21 2012
STATUS
approved