A031936 Lower prime of a difference of 18 between consecutive primes.

523, 1069, 1259, 1381, 1759, 1913, 2161, 2503, 2861, 3803, 3889, 4159, 4373, 4423, 4463, 4603, 4703, 4733, 5059, 5209, 5483, 6011, 6229, 6451, 6529, 6581, 6619, 7159, 7351, 7393, 7433, 7459, 7621, 7883, 8191, 8761, 9109, 9293, 9749

Offset: 1

Author

Jeff Burch

Keywords

• nonn

Comments

Subsequence of A153418: a(1)=523=A153418(46), a(2)=1069=A153418(80), etc. - Zak Seidov, Sep 13 2015

No terms are congruent to 7 mod 10. - Michel Marcus, Sep 14 2015

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
• Index entries for primes, gaps between

Crossrefs

Cf. A153418.

Programs

Magma

[p: p in PrimesUpTo(10000) | NextPrime(p)-p eq 18]; // Bruno Berselli, Apr 09 2013

Mathematica

Transpose[Select[Partition[Prime[Range[1300]], 2, 1], Last[#] - First[#] == 18 &]][[1]] (* Bruno Berselli, Apr 09 2013 *)

PARI

isok(p) = isprime(p) && (nextprime(p+1) == p+18); \\ Michel Marcus, Sep 14 2015

Formula

a(n) = prime(A320707(n)). - R. J. Mathar, Apr 30 2024