A156155 Numbers k such that prime(prime(k)) = 2 (mod prime(k)), where prime(k) = A000040(k) is the k-th prime.

2, 6, 21, 51892, 1686970

Offset: 1

Author

M. F. Hasler, Feb 04 2009

Keywords

• nonn
• more

Crossrefs

Cf. A023144, A156154.

Programs

PARI

p=c=0; until(0, until( isprime(c++), p=nextprime(p+1)); (p-2)%c & next; print1( primepi(c)","))

Formula

a(n) = A000720(A156154(n)).

Extensions

a(5) from Jinyuan Wang, Feb 22 2020