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

1, 2, 7, 18, 31, 48, 71, 96, 125, 158, 193, 232, 273, 316, 363, 416, 475, 536, 599, 664, 731, 802, 875, 952, 1033, 1116, 1201, 1290, 1383, 1478, 1579

Offset: 1

Author

Roger L. Bagula, May 16 2007

Keywords

• nonn
• uned

Crossrefs

Cf. A045751.

Programs

Mathematica

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]}]

Formula

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