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A257648
Numbers m such that both p=2*m^2+11 and q=2*p^2+11 are prime.
1
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
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
Sequence in context: A174099 A099005 A336739 * A096360 A039087 A093710
KEYWORD
nonn
AUTHOR
Zak Seidov, Jul 25 2015
STATUS
approved