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 A090563 Numbers n such that 5*n^2 + 5*n + 1 is prime. 16
 1, 2, 3, 4, 5, 6, 7, 11, 13, 14, 15, 16, 17, 19, 21, 22, 24, 25, 26, 30, 32, 35, 36, 38, 43, 44, 49, 52, 54, 55, 60, 61, 62, 63, 66, 69, 70, 71, 73, 74, 79, 80, 81, 82, 85, 87, 88, 93, 94, 101, 104, 106, 107, 109, 110, 112, 114, 115, 117, 123, 127, 128, 131, 135 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS MATHEMATICA Do[s=5*n^2+5*n+1; If[PrimeQ[s], Print[n]], {n, 1, 1000}] PROG (PARI) isok(n) = isprime(5*n^2+5*n+1); \\ Michel Marcus, Apr 30 2016 CROSSREFS Cf. A090562. Sequence in context: A174219 A115037 A280536 * A045745 A054010 A051948 Adjacent sequences:  A090560 A090561 A090562 * A090564 A090565 A090566 KEYWORD nonn AUTHOR Amarnath Murthy, Dec 11 2003 EXTENSIONS More terms from Labos Elemer, Dec 12 2003 Offset corrected by Arkadiusz Wesolowski, Aug 09 2011 STATUS approved

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Last modified October 23 17:19 EDT 2019. Contains 328373 sequences. (Running on oeis4.)