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 A215429 Primes of the form (n^2+2)/6 where n^2+1 is prime. 1
 3, 17, 43, 67, 113, 523, 2017, 2243, 4817, 8363, 9283, 16433, 17713, 19267, 30817, 56843, 81667, 97283, 141067, 149153, 185153, 203873, 271363, 279073, 329473, 398353, 400417, 455953, 472643, 481667, 513923, 519793, 530443, 549643, 670673, 684113, 746243 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The corresponding n are in A215248. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE 3 is in the sequence because, for n = 4, 4^2 + 1 = 17 and (4^2 + 2)/6 = 3 are primes. MATHEMATICA lst={}; Do[ p=n^2+ 1; q=(p+1)/6; If[PrimeQ[p]&&PrimeQ[q], AppendTo[lst, q]], {n, 0, 2500}]; lst Select[(#+1)/6&/@Select[Range[3000]^2+1, PrimeQ], PrimeQ] (* Harvey P. Dale, May 07 2017 *) CROSSREFS Cf. A005574, A002496, A215248. Sequence in context: A322755 A226492 A092347 * A126587 A108126 A106256 Adjacent sequences: A215426 A215427 A215428 * A215430 A215431 A215432 KEYWORD nonn AUTHOR Michel Lagneau, Aug 10 2012 STATUS approved

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Last modified June 21 04:26 EDT 2024. Contains 373540 sequences. (Running on oeis4.)