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 A134702 #2 Oct 19 2017 03:15:08 %S A134702 7,11,11,11,11,11,11,11,29614931,29614931,1172182334669, %T A134702 67667595358511,124204021800149 %N A134702 Initial prime, greater than 5, of a prime chain of length n under the iteration x->2x-5. %e A134702 a(3) = 11 because 11 11*2-5=17 and 17*2-5=29 are primes. %Y A134702 Cf. A084954. %K A134702 nonn,more %O A134702 1,1 %A A134702 _Don Reble_, Nov 07 2007