A257648 Numbers m such that both p=2*m^2+11 and q=2*p^2+11 are prime.

1, 2, 3, 4, 6, 7, 8, 13, 20, 31, 52, 54, 62, 65, 70, 75, 137, 151, 153, 163, 212, 224, 281, 284, 329, 384, 419, 424, 445, 455, 489, 505, 524, 581, 593, 642, 646, 680, 706, 723, 738, 746, 775, 787, 795, 830, 841, 843, 918, 953, 970, 973, 984

Offset

1,2

Comments

Numbers m such that both m and p=2*m^2+11 are terms in A092968. Also, both p and q are terms in A050265.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

n=1: m=1=A092968(2) and p=13=A092968(12),
n=8: m=13=A092968(12) and p=349=A092968(127),
n=9: m=20=A092968(12) and p=811=A092968(251).

Mathematica

Reap[Do[If[PrimeQ[p=2*k^2+11]&&PrimeQ[2*(p)^2+11], Sow[k]], {k, 10^3}]][[2, 1]]
bprQ[n_]:=Module[{p=2n^2+11}, AllTrue[{p, 2p^2+11}, PrimeQ]]; Select[Range[ 1000], bprQ] (* Harvey P. Dale, Jun 16 2022 *)

Crossrefs

Cf. A050265, A092968.

Sequence in context: A174099 A099005 A336739 * A096360 A039087 A093710

Adjacent sequences: A257645 A257646 A257647 * A257649 A257650 A257651

Keyword

nonn

Author

Zak Seidov, Jul 25 2015

Status

approved