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A213559
Principal diagonal of the convolution array A213558.
3
1, 91, 1366, 9542, 43535, 151313, 435324, 1089804, 2452269, 5071495, 9794290, 17873362, 31098587, 51953981, 83802680, 131102232, 199652505, 296878515, 432150478, 617143390, 866238439, 1196968553, 1630510388, 2192225060
OFFSET
1,2
LINKS
FORMULA
a(n) = (16/35)*n^7 + (1/2)*n^6 + (1/15)*n^3 - (1/42)*n.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
G.f.: x*(1 + 83*x + 666*x^2 + 1106*x^3 + 421*x^4 + 27*x^5)/(1 - x)^8
MATHEMATICA
(See A213558.)
LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {1, 91, 1366, 9542, 43535, 151313, 435324, 1089804}, 40] (* Harvey P. Dale, Oct 09 2016 *)
CROSSREFS
Sequence in context: A020316 A221815 A195221 * A120756 A027787 A333112
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 17 2012
STATUS
approved