A156148 Numbers k such that prime(prime(k)) + 2 == 0 (mod prime(k)), where prime(p)=A000040(p) is the p-th prime.

5, 20, 51891, 51893

Offset

1,1

Comments

No additional terms up to k=500,000. - Harvey P. Dale, Jul 12 2022

Links

Table of n, a(n) for n=1..4.

Formula

a(n) = A000720(A156149(n)).

Mathematica

Select[Range[52000], Mod[Prime[Prime[#]]+2, Prime[#]]==0&] (* Harvey P. Dale, Jul 12 2022 *)

Prog

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

Crossrefs

Cf. A156155.

Sequence in context: A213148 A202860 A344709 * A224867 A156824 A053002

Adjacent sequences: A156145 A156146 A156147 * A156149 A156150 A156151

Keyword

hard,more,nonn

Author

M. F. Hasler, Feb 04 2009

Status

approved