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 A173627 Primes p such that p^2 + 6, p^2 + 12 and p^2 + 18 are all prime. 2
 5, 19, 61, 971, 1451, 2711, 3061, 3449, 6011, 15139, 15241, 21821, 27851, 39839, 51749, 62459, 75679, 76081, 82591, 97001, 121039, 121441, 122299, 135581, 161569, 162671, 196681, 196831, 200881, 214741, 217271, 222931, 242069, 243119, 254161 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For p > 2, p^2 + 24 is composite (divisible by 5). - Zak Seidov, Sep 07 2018 LINKS Zak Seidov, Table of n, a(n) for n = 1..1800 MATHEMATICA okQ[n_]:=Module[{p2=n^2}, And@@PrimeQ[{p2+6, p2+12, p2+18}]]; Select[Prime[Range[30000]], okQ] (* Harvey P. Dale, Dec 18 2010 *) PROG (Magma)[p: p in PrimesUpTo(600000)|IsPrime(p^2+6) and IsPrime(p^2+12) and IsPrime(p^2+18)] // Vincenzo Librandi, Dec 13 2010 (PARI) isok(p) = isprime(p) && isprime(p^2+6) && isprime(p^2+12) && isprime(p^2+18); \\ Michel Marcus, Sep 08 2018 CROSSREFS Cf. A062718 (p and p^2 + 6 are both prime). Sequence in context: A355492 A212339 A072111 * A295288 A141397 A305779 Adjacent sequences: A173624 A173625 A173626 * A173628 A173629 A173630 KEYWORD nonn AUTHOR Zak Seidov, Nov 09 2010 STATUS approved

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Last modified December 3 02:05 EST 2023. Contains 367530 sequences. (Running on oeis4.)