login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107615 Coefficient list length of Poincaré-like polynomials made from A047845, indices of 4*n+1 nonprimes as the m(i) exponents. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..31.

FORMULA

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

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]}]

CROSSREFS

Cf. A045751.

Sequence in context: A104310 A301325 A001114 * A195605 A184096 A136583

Adjacent sequences:  A107612 A107613 A107614 * A107616 A107617 A107618

KEYWORD

nonn,uned

AUTHOR

Roger L. Bagula, May 16 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 10 14:50 EDT 2020. Contains 336381 sequences. (Running on oeis4.)