cp's OEIS Frontend

A231818 Least positive k such that k*n^n - 1 is a prime, or 0 if no such k exists.

%I A231818 #6 Nov 15 2013 00:28:37
%S A231818 3,1,2,5,6,3,6,39,18,6,12,19,8,23,10,3,76,13,90,26,52,45,124,12,60,27,
%T A231818 10,99,126,11,50,27,28,59,6,80,122,71,110,21,72,111,590,147,178,84,
%U A231818 238,12,138,236,10,53,6,60,98,72,620,30,166,5,98,18,22,384,126
%N A231818 Least positive k such that k*n^n - 1 is a prime, or 0 if no such k exists.
%t A231818 Table[k = 1; While[! PrimeQ[k*n^n - 1], k++]; k, {n, 65}] (* _T. D. Noe_, Nov 15 2013 *)
%Y A231818 Cf. A035092 (least k such that k*(n^2)+1 is a prime).
%Y A231818 Cf. A175763 (least k such that k*(n^n)+1 is a prime).
%Y A231818 Cf. A035093 (least k such that k*n!+1    is a prime).
%Y A231818 Cf. A193807 (least k such that n*(k^2)+1 is a prime).
%Y A231818 Cf. A231119 (least k such that n*(k^k)+1 is a prime).
%Y A231818 Cf. A057217 (least k such that n*k!+1    is a prime).
%Y A231818 Cf. A034693 (least k such that n*k +1    is a prime).
%Y A231818 Cf. A231819 (least k such that k*(n^2)-1 is a prime).
%Y A231818 Cf. A083663 (least k such that k*n!-1    is a prime).
%Y A231818 Cf. A231734 (least k such that n*(k^2)-1 is a prime).
%Y A231818 Cf. A231735 (least k such that n*(k^k)-1 is a prime).
%Y A231818 Cf. A231820 (least k such that n*k!-1    is a prime).
%Y A231818 Cf. A053989 (least k such that n*k -1    is a prime).
%K A231818 nonn
%O A231818 1,1
%A A231818 _Alex Ratushnyak_, Nov 13 2013