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A039826
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Largest coefficient in expansion of Product_{i=1..n} (1 + q^i + q^(2i)).
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3
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1, 2, 3, 7, 15, 36, 87, 217, 549, 1423, 3735, 9911, 26513, 71581, 194681, 532481, 1464029, 4045117, 11225159, 31268577, 87404465, 245101771, 689323849, 1943817227, 5494808425, 15568077235, 44200775239, 125739619467, 358347118257, 1022994133467, 2925044957099, 8376049588815, 24018964753341
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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nmax = 28; d = {1}; a1 = {};
Do[
n0s = Table[0, {n}];
d = Join[d, n0s, n0s] + Join[n0s, d, n0s] + Join[n0s, n0s, d];
AppendTo[a1, Last[Union[d]]];
, {n, nmax}];
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PROG
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(PARI) a(n)=vecmax(Vec(prod(k=1, n, 1+x^k+x^(2*k))));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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