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 A100408 Numbers n such that n^n-2 is prime. 8
 2, 7, 19, 21, 25, 49, 51, 1071 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Except for the first term all terms are odd. Numbers n such that n^n+7 is prime gives the (as yet) too-short sequence 2,4,6,32,... If it exists, a(9) > 25000. - Robert Price, Apr 25 2019 LINKS Table of n, a(n) for n=1..8. EXAMPLE 51 is in the sequence because 51^51-2 is prime. 1071^1071-2 is a probable prime. MATHEMATICA Do[If[PrimeQ[n^n-2], Print[n]], {n, 1111}] PROG (PARI) is(n)=ispseudoprime(n^n-2) \\ Charles R Greathouse IV, Feb 20 2017 CROSSREFS Cf. A100407. Sequence in context: A218684 A337614 A343908 * A259370 A103034 A038952 Adjacent sequences: A100405 A100406 A100407 * A100409 A100410 A100411 KEYWORD more,nonn AUTHOR Farideh Firoozbakht, Nov 19 2004 STATUS approved

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Last modified August 9 13:53 EDT 2024. Contains 375042 sequences. (Running on oeis4.)