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 A204139 #6 Oct 30 2018 10:31:02 %S A204139 5227,7673,8147,8269,8353,8647,8803,9043,9091 %N A204139 Primes p such that 9p^2 is a penholodigital square (A036744). %C A204139 Subsequence of A071519/3. %Y A204139 Cf. A036744, A071519. %K A204139 nonn,base,fini,full %O A204139 1,1 %A A204139 _Zak Seidov_, Jan 11 2012