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 A219117 Numbers n such that n^1+n+1, n^2+n+1, n^3+n+1 and n^4+n+1 are all prime. 4
 1, 2, 5, 6, 69, 131, 426, 1665, 2129, 2696, 5250, 7929, 9689, 13545, 14154, 14286, 16434, 19760, 25739, 27809, 29631, 36821, 41819, 46619, 48321, 59030, 60500, 61955, 62321, 73610, 77685, 79646, 80535, 82655, 85251, 86996, 91014, 96566, 97739, 105939, 108240 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Israel, Table of n, a(n) for n = 1..1000 MAPLE select(t -> andmap(isprime, [2*t+1, t^2+t+1, t^3+t+1, t^4+t+1]), [\$1..2*10^5]); # Robert Israel, Dec 15 2017 PROG (Haskell) a219117_list = filter (all (== 1) . p) [1..] where    p x = map (a010051 . (+ (x + 1)) . (x ^)) [1..4] CROSSREFS Cf. A057683 (subsequence); A010051. Sequence in context: A055877 A288799 A281378 * A111190 A244434 A176007 Adjacent sequences:  A219114 A219115 A219116 * A219118 A219119 A219120 KEYWORD nonn AUTHOR Reinhard Zumkeller, Nov 12 2012 STATUS approved

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Last modified June 15 11:22 EDT 2021. Contains 345048 sequences. (Running on oeis4.)