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

67, 877

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..2.

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.

Prog

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

Crossrefs

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

Sequence in context: A106106 A093942 A166802 * A254640 A093267 A032651

Adjacent sequences: A212554 A212555 A212556 * A212558 A212559 A212560

Keyword

nonn,hard,bref,more

Author

Felix Fröhlich, May 21 2012

Status

approved