A049437 Primes p such that p+2 and p+8 are also primes but p+6 is not.

3, 29, 59, 71, 149, 269, 431, 569, 599, 1031, 1061, 1229, 1289, 1319, 1451, 1619, 2129, 2339, 2381, 2549, 2711, 2789, 3299, 3539, 4019, 4049, 4091, 4649, 4721, 5099, 5441, 5519, 5639, 5741, 5849, 6269, 6359, 6569, 6701, 6959, 7211

Offset

1,1

Comments

p+4 is not prime here except for p=3.

Links

Iain Fox, Table of n, a(n) for n = 1..10000 (first 1000 terms from R. J. Mathar)

Example

p=29 is the smallest prime so that p, p+2 and p+8 are consecutive primes.

Maple

select(p -> isprime(p) and isprime(p+2) and isprime(p+8) and not isprime(p+6), [3, seq(i, i=5..10000, 6)]); # Robert Israel, Nov 20 2017

Mathematica

{3}~Join~Select[Partition[Prime@ Range[10^3], 3, 1], Differences@ # == {2, 6} &][[All, 1]] (* Michael De Vlieger, Nov 20 2017 *)

Prog

(Magma) [p: p in PrimesUpTo(8000)| IsPrime(p+2) and IsPrime(p+8) and not IsPrime(p+6) ] // Vincenzo Librandi, Jan 28 2011
(PARI) lista(nn) = forprime(p=3, nn, if(isprime(p+2) && isprime(p+8) && !isprime(p+6), print1(p, ", "))) \\ Iain Fox, Nov 20 2017

Crossrefs

Cf. A007530, A023202, A031926, A046134, A046138, A049436, A049438, A046138.

Subsequence of A001359. - R. J. Mathar, Feb 10 2013

Sequence in context: A107189 A059761 A210360 * A171409 A220953 A031912

Adjacent sequences: A049434 A049435 A049436 * A049438 A049439 A049440

Keyword

nonn

Author

Labos Elemer

Status

approved