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A213766
Principal diagonal of the convolution array A213765.
3
1, 5, 24, 83, 263, 776, 2201, 6077, 16488, 44211, 117615, 311232, 820641, 2158645, 5669096, 14872483, 38989367, 102165928, 267628569, 700924525, 1835493016, 4806144675, 12583939679, 32947361088, 86260987393, 225840387941
OFFSET
1,2
FORMULA
a(n) = 5*a(n-1) - 6*a(n-2) - 3*a(n-3) + 6*a(n-4) + a(n-5) - a(n-6).
G.f.: f(x)/g(x), where f(x) = x*(1 + 5*x - 10*x^2) and g(x) = (1 - 3*x + 2*x^2 )^2.
MATHEMATICA
(See A213765.)
CROSSREFS
Sequence in context: A274723 A006328 A390534 * A000347 A270906 A268587
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 21 2012
STATUS
approved