A248874 Primitive prime factors of the cyclotomic polynomial sequence Phi(10,k) in the order in which they occur.

11, 61, 5, 41, 521, 101, 191, 331, 1181, 9091, 13421, 19141, 2411, 71, 31, 1531, 61681, 9041, 2251, 152381, 185641, 224071, 211, 5791, 9161, 431, 1021, 271, 53951, 401, 71261, 21821, 251, 4051, 1151041, 259631, 132631, 241, 6781, 1824841, 2031671, 41011

Offset

1,1

Comments

Phi(10,k) = k^4 - k^3 + k^2 - k + 1.

Note that except for a(3), all terms end with the digit 1.

Links

Robert Price, Table of n, a(n) for n = 1..1218

Mathematica

prim = {}; Do[prim = Join[prim, Complement[First /@ FactorInteger[Cyclotomic[10, k]], prim]], {k, 1000}]; prim

Crossrefs

Cf. A005529.

Sequence in context: A055826 A324622 A156704 * A073625 A307628 A106993

Adjacent sequences: A248871 A248872 A248873 * A248875 A248876 A248877

Keyword

nonn

Author

Robert Price, Mar 14 2015

Status

approved