A103912 Numbers k such that 2*prime(k)+1, 2*prime(k+1)+1, 2*prime(k+2)+3 and 2*prime(k+3)-3 are also consecutive primes.

20382, 409331, 588060, 718919, 892113, 1583347, 1680668, 2909044, 4104093, 4335628, 4589071, 4910417, 5167262, 5227231, 5276556, 5667695, 6228570, 7874791, 8307560, 8923874, 9004943, 9098100, 9616214, 9792649, 10374603, 12293364, 12884611, 13450210, 13798661, 13877345

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Mathematica

s={}; n=1; p1=2; p2=3; p3=5; Do[p4 = NextPrime[p3]; If[PrimeQ[2*p1+1] && (np = NextPrime[2*p1+1]) == 2*p2+1 && (np2 = NextPrime[np]) == 2*p3+3 && NextPrime[np2] == 2*p4-3, AppendTo[s, n]]; p1=p2; p2=p3; p3=p4; n++, {10^5}]; s (* Amiram Eldar, Jul 23 2021 *)

Crossrefs

Cf. A103911, A103913.

Sequence in context: A156408 A045815 A182294 * A256104 A269279 A234552

Adjacent sequences: A103909 A103910 A103911 * A103913 A103914 A103915

Keyword

nonn

Author

Pierre CAMI, Feb 21 2005

Extensions

More terms from Amiram Eldar, Jul 23 2021

Status

approved