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 A050731 #5 Oct 16 2019 01:19:30 %S A050731 0,2,4,5,7,9,10,12,16 %N A050731 Decimal expansion of 11^n contains no pair of consecutive equal digits (probably finite). %e A050731 11^16 = 45949729863572161. %Y A050731 Cf. A030706. %K A050731 nonn,base %O A050731 0,2 %A A050731 _Patrick De Geest_, Sep 15 1999