%I #9 Feb 29 2024 17:53:41
%S 1,1,1,1,3,2,3,2,20,4,5,2,9,2,27,7,12,3,3,2,3,6,6,1,18,8,2,17,2,14,55,
%T 1,18,4,59,18,30,26,32,3,14,59,42,35,40,22,7,17,26,6,28,3,15,11,6,32,
%U 30,18,14,4,85,3,1,65,13,64,7,18,40,8,68,5,5,6,107,7,88,25,6,3,1,21,8,12,9
%N Least k(n) such that k(n)*6^n*(6^n-1)+j is prime with j= -1 or 1 or both
%C When n increases sum k(n) for i=1 to n / sum n for i=1 to n tends to log(6)/4.5
%H Pierre CAMI, <a href="/A153092/b153092.txt">Table of n, a(n) for n = 1..1000</a>
%e 1*6^1*(6^1-1)-1=29 prime as 31 so k(1)=1
%t lkn[n_]:=Module[{c=6^n (6^n-1),k=1},While[NoneTrue[k*c+{1,-1},PrimeQ],k++];k]; Array[lkn,90] (* _Harvey P. Dale_, Feb 29 2024 *)
%Y A152414, A152090, A152091, A152093, A152094, A152095
%K nonn
%O 1,5
%A _Pierre CAMI_, Dec 18 2008