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 A057988 #6 May 20 2017 21:53:29 %S A057988 4,6,9,14,21,23,30,34,36,39,46,50,52,57,59,62,67,74,78,80,85,87,90,97, %T A057988 99,102,107,114,116,123,127,129,134,136,139,146,148,151,156,163,167, %U A057988 169,172,177,184,186,193,197,199,202,209,213 %N A057988 Positions of 2 in A057985. %H A057988 Clark Kimberling, <a href="/A057988/b057988.txt">Table of n, a(n) for n = 1..10000</a> %Y A057988 Cf. A057985, A057986, A057987. %K A057988 nonn %O A057988 1,1 %A A057988 _Clark Kimberling_, Oct 30 2000