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 A023216 Numbers n such that n and 4n + 9 are both prime. 4
 2, 5, 7, 11, 13, 23, 37, 41, 43, 47, 67, 71, 97, 103, 113, 137, 151, 163, 167, 173, 181, 191, 197, 211, 233, 251, 263, 271, 277, 293, 307, 317, 397, 401, 421, 431, 433, 463, 467, 491, 557, 571, 587, 593, 607, 617, 653, 683, 727, 757, 811, 823, 863, 877, 881, 883, 887, 907 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..4000 MATHEMATICA Select[Prime[Range[2000]], PrimeQ[4# + 9]&] (* Vincenzo Librandi, Feb 02 2014 *) PROG (MAGMA) [n: n in [0..1000] | IsPrime(n) and IsPrime(4*n+9)]; // Vincenzo Librandi, Nov 19 2010 CROSSREFS Sequence in context: A256396 A291280 A120330 * A079449 A236071 A038885 Adjacent sequences:  A023213 A023214 A023215 * A023217 A023218 A023219 KEYWORD nonn,easy AUTHOR STATUS approved

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Last modified September 18 20:22 EDT 2019. Contains 327181 sequences. (Running on oeis4.)