A058857 Numbers n such that the trinomial x^n + x + 1 is irreducible over GF(7).

0, 1, 3, 4, 9, 33, 52, 177, 1042, 2799, 5950, 8595, 19438

Offset: 1

Author

Robert G. Wilson v, Jan 05 2001

Keywords

• nonn
• more

Comments

No other terms <= 4000. - Eric M. Schmidt, Feb 10 2014

Next term > 2*10^4. [Joerg Arndt, Mar 02 2016]

Crossrefs

Cf. A002475 (GF(2)), A058334 (GF(5)).

Programs

PARI

isok(n) = polisirreducible(Mod(1, 7)*(x^n + x + 1)); \\ Michel Marcus, Feb 11 2014

Sage

def isA058857(n) : x = GF(7)['x'].0; return (x^n + x + 1).is_irreducible() # Eric M. Schmidt, Feb 10 2014

Extensions

a(1), a(2) and a(10) from Eric M. Schmidt, Feb 10 2014

a(11) - a(13) from Joerg Arndt, Mar 02 2016