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 A176272 #2 Mar 30 2012 17:36:45 %S A176272 61,66666667,6666666666666666666666666666666666666666641 %N A176272 Primes of the form 2(10^n-1)/3 * 10^ceiling(log_10(n+1)) + n. %C A176272 Equivalently, primes with decimal representation as n 6's with n's decimal representation concatenated. The next term is too large to include (2433 decimal digits). %Y A176272 Cf. A176090 (corresponding n), A065589, A037065. %K A176272 nonn,bref %O A176272 1,1 %A A176272 _Rick L. Shepherd_, Apr 13 2010