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A305063
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a(n) = 110*2^n + 118.
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3
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228, 338, 558, 998, 1878, 3638, 7158, 14198, 28278, 56438, 112758, 225398, 450678, 901238, 1802358, 3604598, 7209078, 14418038, 28835958, 57671798, 115343478, 230686838, 461373558, 922746998, 1845493878, 3690987638, 7381975158, 14763950198, 29527900278, 59055800438, 118111600758, 236223201398
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OFFSET
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0,1
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COMMENTS
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a(n)(n>=0) is the second Zagreb index of the dendrimer graph K[n], defined pictorially in the Ghorbani et al. reference (see Figs. 9, 10, and 11).
The second Zagreb index of a simple connected graph is the sum of the degree products d(i)d(j) over all edges ij of the graph.
The M-polynomial of K[n] is M(K[n]; x, y) = 2*2^n*x*y^3 + 2*(2^n + 2)*x^2*y^2 + (2^4*2^n -4)*x^2*y^3 + 14*x^3*y^3.
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LINKS
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FORMULA
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MAPLE
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seq(110*2^n+118, n = 0 .. 40);
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MATHEMATICA
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PROG
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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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