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 A103959 #7 Apr 18 2013 16:56:44 %S A103959 2,3,3,3,3,3,5,7,3,11,13,3,11,3,3,3,5,3,3,3,7,19,11,5,7,5,3,23,7,3,3, %T A103959 5,3,7,5,31,7,3,3,5,17,3,3,3,5,19,3,7,29,7,5,5,61,3,3,3,11,3,3,11,7,3, %U A103959 3,5,3,5,3,3,3,7,11,11,19,3,61,5,29,7,3,7,17 %N A103959 Minimum prime p such that prime(n)*p - 2 is prime. %C A103959 Conjecture: a(n) <= prime(n). Tested to n=10000. %H A103959 T. D. Noe, <a href="/A103959/b103959.txt">Table of n, a(n) for n = 1..10000</a> %e A103959 Prime(1)*2-2=2 is prime, so a(1)=2; %e A103959 Prime(2)*3-2=7 is prime, so a(2)=3; %t A103959 Table[p=Prime[n]; k=1; pk=Prime[k]; cp=p*pk-2; While[ !PrimeQ[cp], k=k+1; pk=Prime[k]; cp=p*pk-2]; pk, {n, 100}] %K A103959 easy,nonn %O A103959 1,1 %A A103959 _Lei Zhou_, Feb 22 2005