A145487 Numbers k such that 6k+5 is prime and 12k+5 is also prime

0, 1, 2, 3, 4, 7, 8, 9, 11, 14, 16, 21, 22, 24, 29, 32, 37, 38, 42, 43, 46, 51, 58, 63, 64, 66, 71, 73, 77, 79, 81, 84, 92, 98, 99, 102, 106, 107, 108, 113, 119, 123, 134, 136, 142, 143, 156, 157, 158, 162, 184, 191, 196, 198, 203, 212, 217, 219, 227, 228, 238, 241, 246

Offset

1,3

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Formula

a(n) = (A145471(n)-5)/12.

Mathematica

aa = {}; k = 5; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, (Prime[n] - 5)/12]], {n, 1, 500}]; aa
Select[Range[0, 250], PrimeQ[6 # + 5] && PrimeQ[12 # + 5] &] (* Ivan Neretin, Jan 21 2017 *)
Select[Range[0, 250], AllTrue[5+{6#, 12#}, PrimeQ]&] (* Harvey P. Dale, Dec 20 2022 *)

Crossrefs

Cf. A063908-A063913, A092109, A145471-A145490.

Sequence in context: A022162 A022164 A074215 * A061856 A105941 A276876

Adjacent sequences: A145484 A145485 A145486 * A145488 A145489 A145490

Keyword

nonn

Author

Artur Jasinski, Oct 11 2008

Status

approved