A235871 Primes p such that p+2, p+24 and p+246 are also primes.

5, 17, 107, 617, 857, 1277, 1487, 2087, 3167, 3557, 4217, 6947, 7457, 7877, 10067, 12917, 13217, 14387, 15137, 17657, 20897, 21317, 22367, 22697, 27407, 27527, 27917, 28547, 29207, 29387, 30467, 31727, 32117, 33287, 33617, 35507, 36107, 47657, 49367, 49787

Offset

1,1

Comments

All the terms in the sequence are congruent to 5 mod 6.

The constants in the definition (2, 24 and 246) are the concatenation of first even digits 2,4 and 6.

Links

K. D. Bajpai, Table of n, a(n) for n = 1..5178

Example

a(2) = 17 is a prime: 17+2 = 19, 17+24 = 41 and 17+246 = 263 are also prime.
a(3) = 107 is a prime: 107+2 = 119, 107+24 = 131 and 107+246 = 353 are also prime.

Maple

KD:= proc() local a, b, d, e; a:= ithprime(n); b:=a+2; d:=a+24; e:=a+246; if isprime(b) and isprime(d) and isprime(e) then return (a) :fi; end: seq(KD(), n=1..15000);

Mathematica

KD = {}; Do[p = Prime[n]; If[PrimeQ[p + 2] && PrimeQ[p + 24] && PrimeQ[p + 246], AppendTo[KD, p]], {n, 15000}]; KD
c = 0; p = Prime[n]; Do[If[PrimeQ[p + 2] && PrimeQ[p + 24] && PrimeQ[p + 246], c = c + 1; Print[c, " ", Prime[n]]], {n, 1, 5000000}];  (* b - file *)

Prog

(PARI) s=[]; forprime(p=2, 50000, if(isprime(p+2) && isprime(p+24) && isprime(p+246), s=concat(s, p))); s \\ Colin Barker, Apr 21 2014

Crossrefs

Cf. A000040, A023200, A046136, A230223, A237890.

Sequence in context: A143562 A261425 A297476 * A240803 A098028 A100301

Adjacent sequences: A235868 A235869 A235870 * A235872 A235873 A235874

Keyword

nonn

Author

K. D. Bajpai, Apr 21 2014

Status

approved