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A213079 Primes p such that 2p^2-1, 3p^2-2 and 4p^2-3 are also prime. 7
409, 941, 6299, 10459, 11131, 11551, 15581, 16831, 17321, 17569, 25771, 25969, 26701, 31511, 36131, 40529, 43781, 50231, 52879, 54631, 54779, 56711, 60271, 61331, 70321, 71081, 83101, 83299, 85931, 100649, 110681, 116381, 118409, 118751, 120641, 130469 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Subsequence of A213078:
a(1) = 409 = A213078(4) = A106483(29) = A000040(80),
a(2) = 941 = A213078(7) = A106483(50) = A000040(160).
LINKS
MATHEMATICA
Select[Prime[Range[20000]], PrimeQ[2 #^2 - 1] && PrimeQ[3 #^2 - 2] && PrimeQ[4 #^2 - 3] &] (* T. D. Noe, Jun 06 2012 *)
Select[Prime[Range[12500]], AllTrue[{2#^2-1, 3#^2-2, 4#^2-3}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 11 2015 *)
PROG
(Magma) [p: p in PrimesUpTo(140000) | IsPrime(2*p^2-1) and IsPrime(3*p^2-2) and IsPrime(4*p^2-3)]; // Vincenzo Librandi, Apr 08 2013
CROSSREFS
Sequence in context: A212604 A316934 A052354 * A260173 A321151 A052376
KEYWORD
nonn,easy
AUTHOR
Zak Seidov, Jun 04 2012
STATUS
approved

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Last modified May 14 10:34 EDT 2024. Contains 372532 sequences. (Running on oeis4.)