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A107615 Coefficient list length of Poincaré-like polynomials made from A047845, indices of 4*n+1 nonprimes as the m(i) exponents. 0

%I

%S 1,2,7,18,31,48,71,96,125,158,193,232,273,316,363,416,475,536,599,664,

%T 731,802,875,952,1033,1116,1201,1290,1383,1478,1579

%N Coefficient list length of Poincaré-like polynomials made from A047845, indices of 4*n+1 nonprimes as the m(i) exponents.

%F P(m) = Product[1 + t^(2*A045751(n) + 1), {n, 1, m}] a(n) = Length[CoefficientList[P(n),x]].

%t a = Flatten[Table[If[PrimeQ[4*n + 1] == False, n, {}], {n, 0, 50}]]; Table[Length[CoefficientList[Product[1 + t^(2*a[[n]] + 1), {n, 1, m}], t]], { m, 0, Length[a]}]

%Y Cf. A045751.

%K nonn,uned

%O 1,2

%A _Roger L. Bagula_, May 16 2007

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Last modified September 29 02:49 EDT 2020. Contains 337420 sequences. (Running on oeis4.)