A031931 Upper prime of a difference of 12 between consecutive primes.

211, 223, 479, 521, 631, 673, 809, 1009, 1213, 1249, 1319, 1471, 1511, 1523, 1543, 1721, 1801, 1823, 1901, 2081, 2111, 2309, 2411, 2459, 2591, 2633, 2789, 2939, 3061, 3079, 3181, 3203, 3271, 3343, 3359, 3511, 3571, 3671, 3943, 4001, 4091, 4111, 4409, 4421

Offset: 1

Author

Jeff Burch

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Index entries for primes, gaps between

Crossrefs

Cf. A031925 (difference of 6).

Programs

Mathematica

Select[Partition[Prime[Range[700]],2,1],#[[2]]-#[[1]]==12&][[All,2]] (* Harvey P. Dale, Dec 28 2018 *)

PARI

isok(p) = isprime(p) && (p-precprime(p-1) == 12); \\ Michel Marcus, Jun 24 2022

Extensions

Corrected and extended by Harvey P. Dale, Dec 28 2018