This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A153093 #8 Jun 27 2025 12:03:36 %S A153093 1,1,1,2,9,1,2,1,1,5,13,1,6,1,6,14,4,4,7,5,6,5,12,3,6,3,9,3,20,9,14,7, %T A153093 43,22,5,11,4,4,48,14,8,56,36,7,83,47,47,1,2,74,15,12,22,15,17,47,20, %U A153093 20,5,8,12,26,6,26,55,16,32,45,24,46,19,58,6,29,19,26,83,45,17,48,6,16,152 %N A153093 Least k(n) such that k(n)*7^n*(7^n-1)+j is prime with j= -1 or 1 or both. %C A153093 When n increases sum k(n) for i=1 to n / sum n for i=1 to n tends to log(7)/3.7. %H A153093 Pierre CAMI, <a href="/A153093/b153093.txt">Table of n, a(n) for n = 1..1000</a> %e A153093 1*7^1*(7^1-1)-1=41 prime as 43 so k(1)=1. %Y A153093 A152414, A152090, A152091, A152092, A152094, A152095. %K A153093 nonn %O A153093 1,4 %A A153093 _Pierre CAMI_, Dec 18 2008