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 A153086 Numbers n such that 4*n+7 is not prime 1
 2, 5, 7, 8, 11, 12, 14, 17, 20, 21, 22, 23, 26, 27, 28, 29, 32, 34, 35, 37, 38, 41, 42, 44, 45, 47, 49, 50, 52, 53, 56, 57, 59, 60, 62, 63, 65, 67, 68, 70, 71, 72, 73, 74, 77, 78, 79, 80, 82, 83, 84, 86, 87, 89, 91, 92, 95, 96, 97, 98, 99, 100, 101, 102, 104, 105, 107 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 EXAMPLE *; 2, *; *, 7, *; 5, *, 14, *; *, 12, *, 23, *; 8, *, 21, *, 34, *; *, 17, *, 32, *, 47, *; etc. where * marks the non-integer values of (2*n*k + k + n - 3)/2 with n >= k >= 1. - Vincenzo Librandi, Nov 21 2012 MATHEMATICA Select[Range[200], !PrimeQ[4# + 7] &] (* Vincenzo Librandi, Nov 21 2012 *) PROG (MAGMA) [n: n in [1..120] | not IsPrime(4*n + 7)]; // Vincenzo Librandi, Nov 21 2012 CROSSREFS Cf. A089986, A153053. Sequence in context: A299232 A153083 A140592 * A032784 A277266 A047268 Adjacent sequences:  A153083 A153084 A153085 * A153087 A153088 A153089 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Dec 18 2008 STATUS approved

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Last modified January 24 01:05 EST 2020. Contains 331178 sequences. (Running on oeis4.)