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 A024815 #12 Jul 25 2019 01:00:41
%S A024815 0,2,5,8,11,52174,573204,42781604,288632526
%N A024815 a(n) = least k such that tan(k) < tan(a(n-1)), for n >= 1, with a(0) = 0.
%o A024815 (PARI) a(nn) = {last = 0; lastk = 0; print1(lastk, ", "); for (i=1, nn, k = lastk; while (tan(k) >= last, k++;); print1(k, ", "); last = tan(k); lastk = k;);} \\ _Michel Marcus_, Mar 23 2013
%K A024815 nonn,more
%O A024815 0,2
%A A024815 _Clark Kimberling_
%E A024815 a(7) from _Michel Marcus_, Mar 23 2013
%E A024815 a(8) from _Sean A. Irvine_, Jul 24 2019