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 A073310 #5 Mar 30 2012 17:22:25
%S A073310 1,1,1,3,1,1,3,1,1,3,1,5,3,1,1,5,3,1,3,1,1,3,1,5,3,1,5,3,1,1,5,3,1,3,
%T A073310 1,1,5,3,1,3,1,5,3,1,11,5,3,1,3,1,1,3,1,1,3,1,17,11,9,11,5,3,1,3,1,5,
%U A073310 3,1,1,9,9,5,3,1,1,5,3,1,5,3,1,3,1,5,3,1,5,3,1,1,9,9,5,3,1,1,3,1,1,11,9,29
%N A073310 a(n) is the smallest number k such that 2+k and 2n+k are both prime.
%C A073310 Conjecture: a(n) < 2n. See A073316 for a generalization for all positive even numbers less than 2n.
%e A073310 a(45) = 11 because 11 is the smallest number yielding two primes when added to 2 and 90. This is the first instance where this sequence differs from A060266.
%t A073310 maxN=200; lst={}; For[n=1, n<=maxN, n++, k=1; While[k<2n&&!(PrimeQ[k+2]&&PrimeQ[k+2n]), k=k+2]; AppendTo[lst, k]; If[k>2n, Print["Failure at n = ", n]]]; lst
%Y A073310 Cf. A060266, A073316.
%K A073310 easy,nonn
%O A073310 1,4
%A A073310 _T. D. Noe_, Aug 02 2002