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 A048827 #9 Dec 19 2015 13:17:08 %S A048827 2,3,19,173,3976733 %N A048827 a(n) = least k such that A047988(k) = n. %C A048827 Values calculated by Thomas Kantke (bytes.more(AT)ibm.net). %K A048827 nonn,more %O A048827 0,1 %A A048827 _Christian G. Bower_, May 15 1999 %E A048827 Definition corrected by _R. J. Mathar_, Jun 26 2007