A056679 Primes p such that 1 + x + Sum_{q prime <= p} x^q is irreducible over GF(2).

2, 5, 17, 59, 73, 269, 3769, 4327

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Example

a(3) = 17 because 1 + x + x^2 + x^3 + x^5 + x^7 + x^11 + x^13 + x^17 is irreducible over GF(2).

Prog

(PARI) lista(nn) = {my(f=1+x); forprime(p=2, nn, f+=x^p; if(polisirreducible(Mod(1, 2)*f), print1(p, ", "))); } \\ Jinyuan Wang, Apr 15 2020

Crossrefs

Cf. A071642.

Sequence in context: A134128 A119254 A278394 * A084528 A149993 A148413

Adjacent sequences: A056676 A056677 A056678 * A056680 A056681 A056682

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 10 2000

Extensions

a(7)-a(8) from Jinyuan Wang, Apr 15 2020

Status

approved