A247845 - OEIS

A247845

Primes, p, that generate the prime quadruplets, p^2-2p+2k (for k = -2, -1, 1, 2).

5, 62417, 178817, 261017, 419147, 433787, 505607, 876107, 1183337, 1374377, 1620917, 1976987, 3619607, 4146377, 5260487, 5622047, 6399677, 7166147, 7213847, 7743647, 8055167, 10615967, 13277717, 14042117, 14080277, 15331397, 17433407, 17889587, 17963867

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Except for a(1), all other terms in the sequence end in 7.

For a similar list not restricted to primes, see A247882.

LINKS

Table of n, a(n) for n=1..29.

EXAMPLE

5 is in the sequence as it generates the prime quadruplet 5^2-2*5-4=11; 5^2-2*5-2=13; 5^2-2*5+2=17; and, 5^2-2*5+4=19.

PROG

(PARI) lista(nn) = {vk = [-2, -1, 1, 2]; forprime (p=2, nn, nb = 0; for (k=1, 4, nb += isprime(p^2-2*p+2*vk[k]); ); if (nb == 4, print1(p, ", ")); ); } \\ Michel Marcus, Sep 26 2014

(Magma) [p: p in PrimesUpTo(10^7) |IsPrime(p^2-2*p-4) and IsPrime(p^2-2*p-2)and IsPrime(p^2-2*p+2)and IsPrime(p^2-2*p+4)]; // Vincenzo Librandi, Oct 14 2014

CROSSREFS

Cf. A247846 (lesser of prime quadruplets), A247882 (similar but not restricted to primes).

Sequence in context: A356762 A242833 A242478 * A050816 A171981 A145232

Adjacent sequences: A247842 A247843 A247844 * A247846 A247847 A247848

KEYWORD

nonn

AUTHOR

Ray G. Opao, Sep 25 2014

EXTENSIONS

More terms from Michel Marcus, Oct 10 2014

STATUS

approved