A256146 Primitive prime factors of the cyclotomic polynomial sequence Phi(7,k) in the order in which they occur.

7, 127, 1093, 43, 19531, 55987, 29, 4733, 337, 547, 239, 4649, 45319, 659, 4943, 5229043, 8108731, 1743463, 113, 25646167, 449, 80207, 701, 70841, 71, 32719, 631, 3319, 16968421, 5336717, 28771, 321272407, 368089, 4422461, 88009573, 93997, 917087137, 122921

Offset

1,1

Comments

Phi(7,k) = k^6 + k^5 + k^4 + k^3 + k^2 + k + 1.

Links

Robert Price, Table of n, a(n) for n = 1..1511

Mathematica

prim = {}; Do[prim = Join[prim, Complement[First /@ FactorInteger[Cyclotomic[7, k]], prim]], {k, 1000}]; prim

Prog

(PARI) lista(nn) = {vs = []; for (n=1, nn, vp = factor(polcyclo(7, n))[, 1]; for (i=1, #vp, if (!vecsearch(vs, vp[i]), print1(vp[i], ", "); vs = vecsort(concat(vs, vp[i]), , 8); ); ); ); } \\ Michel Marcus, Mar 20 2015

Crossrefs

Cf. A005529, A248874, A256144, A256145.

Sequence in context: A308378 A139987 A061744 * A053716 A088550 A255954

Adjacent sequences: A256143 A256144 A256145 * A256147 A256148 A256149

Keyword

nonn

Author

Robert Price, Mar 16 2015

Status

approved