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 A023593 #10 Jul 08 2015 05:55:32
%S A023593 1,1,1,1,1,3,1,1,1,1,2,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,2,1,1,1,1,1,2,2,
%T A023593 1,1,2,1,1,1,1,1,1,2,1,1,2,1,1,3,1,1,1,1,1,1,2,1,1,1,4,1,1,1,1,1,1,3,
%U A023593 1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,2,1,1,1,1,3,1,1,1,1
%N A023593 Exponent of least prime factor of 2*prime(n)+1.
%e A023593 a(6) = 3 because 2*prime(6)+1 = 27 = 3^3.
%p A023593 A023593 := proc(n)
%p A023593 A067029(2*ithprime(n)+1) ;
%p A023593 end proc: # _R. J. Mathar_, Jul 08 2015
%t A023593 Table[FactorInteger[2*Prime[n] + 1][[1]][[2]], {n, 100}] (* _Clark Kimberling_, Oct 01 2013 *)
%Y A023593 Cf. A067029, A072055.
%K A023593 nonn
%O A023593 1,6
%A A023593 _Clark Kimberling_
%E A023593 Corrected by _Clark Kimberling_, Oct 01 2013