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A305261
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a(n) = 120*2^n - 108.
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4
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12, 132, 372, 852, 1812, 3732, 7572, 15252, 30612, 61332, 122772, 245652, 491412, 982932, 1965972, 3932052, 7864212, 15728532, 31457172, 62914452, 125829012, 251658132, 503316372, 1006632852, 2013265812, 4026531732, 8053063572, 16106127252, 32212254612, 64424509332, 128849018772, 257698037652
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OFFSET
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0,1
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COMMENTS
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a(n) is the number of vertices in the nanostar dendrimer G[n], shown pictorially as NSD[n] in the Rostami et al. reference (Fig. 2).
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LINKS
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FORMULA
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G.f.: 12*(1 + 8*x) / ((1 - x)*(1 - 2*x)).
a(n) = 3*a(n-1) - 2*a(n-2) for n > 1.
(End)
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MAPLE
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seq(120*2^n-108, n = 0 .. 40);
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PROG
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(PARI) Vec(12*(1 + 8*x) / ((1 - x)*(1 - 2*x) + O(x^40))) \\ Colin Barker, May 31 2018
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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