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 A309566 #43 Sep 23 2019 09:24:31 %S A309566 307,130307,309370307,30281172370306703 %N A309566 a(n) is the least prime that can be written as a sequence of primes separated by n single zeros, and where every 0-splitting is prime. %H A309566 Carlos Rivera, <a href="https://www.primepuzzles.net/puzzles/puzz_970.htm">Puzzle 970. A309566</a> %e A309566 a(1) = 307 = A309101(1). %e A309566 130307 is a term since 3, 7, 13, 307, 1303, 130307 are all prime. %Y A309566 Subsequence of A309101. %Y A309566 Cf. A000040 (primes), A038618 (zeroless primes), A056709 (primes with zeros). %K A309566 nonn,base,fini,full %O A309566 1,1 %A A309566 _Michel Marcus_, Aug 08 2019 %E A309566 a(4) from _Daniel Suteu_ and _Giovanni Resta_, Aug 09 2019