A309381 Lucky primes k such that k+6 is also a lucky prime.

7, 31, 37, 67, 73, 613, 991, 1087, 1117, 2467, 3301, 3307, 3607, 4561, 4987, 4993, 6367, 6373, 8263, 8641, 9643, 10903, 11827, 11953, 12373, 12547, 15187, 15901, 17047, 18043, 19603, 20353, 21751, 23671, 25147, 28837, 31033, 31231, 37957, 38707, 38917, 43201, 44383, 46021, 49627

Offset

1,1

Comments

A031157(k) for k such that A309334(k)=6.

The minimum gap between lucky primes (after the first) is 6.

Links

Robert Israel, Table of n, a(n) for n = 1..1615

Example

37 and 37+6=43 are both lucky primes, so 37 is in the sequence.

Maple

N:= 10^5: # for terms <= N
L:= [seq(i, i=1..N+6, 2)]:
for n from 2 while n < nops(L) do
  r:= L[n];
  L:= subsop(seq(r*i=NULL, i=1..nops(L)/r), L);
od:
L:= convert(select(isprime, L), set):
A:= L intersect map(`-`, L, 6):
sort(convert(A, list));

Crossrefs

Cf. A031157, A309334.

Sequence in context: A238664 A272201 A325423 * A276741 A000696 A171733

Adjacent sequences: A309378 A309379 A309380 * A309382 A309383 A309384

Keyword

nonn

Author

Robert Israel, Jul 26 2019

Status

approved