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 A191717 Numbers n such that n*(n-1)^n-(n-1)*n^(n-1)+1 is prime. 1
 3, 5, 18, 23, 78, 131, 177 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE a(1)=3 because 3*2^3-2*3^2+1=7 is prime, a(2)=5 because 5*4^5-4*5^4+1=2621 is prime. PROG (PARI) is(n)=ispseudoprime(n*(n-1)^n-(n-1)*n^(n-1)+1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A191699, A191715. Sequence in context: A007516 A249759 A039584 * A136131 A143546 A069066 Adjacent sequences:  A191714 A191715 A191716 * A191718 A191719 A191720 KEYWORD nonn,hard AUTHOR Juri-Stepan Gerasimov, Jun 12 2011 STATUS approved

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Last modified April 23 10:46 EDT 2021. Contains 343204 sequences. (Running on oeis4.)