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 A084730 Smallest prime of the form k*n! - 1. 2
 2, 3, 5, 23, 239, 719, 5039, 201599, 1088639, 14515199, 159667199, 479001599, 31135103999, 87178291199, 2615348735999, 188305108991999, 711374856191999, 192071211171839999, 3649353012264959999, 12164510040883199999, 2248001455555215359999, 2248001455555215359999 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 LINKS Robert Israel, Table of n, a(n) for n = 2..447 FORMULA a(n) = A083663(n)*n! - 1 = A038700(n!). - Robert Israel, Nov 23 2023 EXAMPLE a(8) = 161599 = 4*8! - 1 is a prime. MAPLE f:= proc(n) local w, k; w:= n!; for k from 1 do if isprime(k*w-1) then return k*w-1 fi od end proc: map(f, [\$1..30]); # Robert Israel, Nov 23 2023 MATHEMATICA Do[k = 1; While[ !PrimeQ[k*n! - 1], k++ ]; Print[k*n! - 1], {n, 2, 20}] PROG (PARI) a(n)=if(n<1, 0, k=1; while(isprime(k*n!-1)==0, k++); k*n!-1) CROSSREFS Cf. A083663, A038700. Sequence in context: A138655 A053708 A137070 * A117696 A256463 A279864 Adjacent sequences: A084727 A084728 A084729 * A084731 A084732 A084733 KEYWORD nonn AUTHOR Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 13 2003 EXTENSIONS Corrected and extended by Benoit Cloitre, Jun 14 2003 STATUS approved

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