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

1,1

Links

Table of n, a(n) for n=1..5.

Formula

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

Prog

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

Crossrefs

Cf. A023144, A156154.

Sequence in context: A367678 A368005 A084392 * A317725 A263486 A182544

Adjacent sequences: A156152 A156153 A156154 * A156156 A156157 A156158

Keyword

nonn,more

Author

M. F. Hasler, Feb 04 2009

Extensions

a(5) from Jinyuan Wang, Feb 22 2020

Status

approved