A212557 Primes p such that (p, p-9) is an irregular pair.

67, 877

Offset: 1

Author

Felix Fröhlich, May 21 2012

Keywords

• nonn
• hard
• bref
• more

Comments

No further terms found up to 163577833 in extended tables (see Buhler link). - Michel Marcus, Apr 17 2014

Links

• Joe Buhler and David Harvey, Irregular primes to 163 million, 2009.
• W. Johnson, Irregular primes and Cyclotomic Invariants, Math. Comp., 1975, Vol. 29, No. 129, pp. 113-120.

Crossrefs

Special instances of A000928. Variant of A088164 (for the terms of A088164, (p, p-3) is an irregular pair).

Programs

PARI

is(n)=lift(Mod(numerator(bernfrac(n-9)), n)==0)
forprime(p=8, , if(is(p), print1(p, ", "))) \\ Felix Fröhlich, Jan 19 2015