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 A091315 #7 Feb 19 2021 20:10:00
%S A091315 1,2,21,402,13805,761154,62523664,7237970648,1132600004910,
%T A091315 231900134422880,60528794385067778,19713593779259862624,
%U A091315 7869483395065035685162,3792402572391137423764584
%N A091315 Number of orbits of length n under the map whose periodic points are counted by A061684.
%C A091315 Old name was: A061684 appears to count the periodic points for a certain map. If so, then this is the sequence of the numbers of orbits of length n.
%H A091315 Y. Puri and T. Ward, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL4/WARD/short.html">Arithmetic and growth of periodic orbits</a>, J. Integer Seqs., Vol. 4 (2001), #01.2.1.
%H A091315 J.-M. Sixdeniers, K. A. Penson and A. I. Solomon, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL4/SIXDENIERS/bell.html">Extended Bell and Stirling Numbers From Hypergeometric Exponentiation</a>, J. Integer Seqs. Vol. 4 (2001), #01.1.4.
%H A091315 Thomas Ward, <a href="http://web.archive.org/web/20081002082625/http://www.mth.uea.ac.uk/~h720/research/files/integersequences.html">Exactly realizable sequences</a>. <a href="/A091112/a091112.pdf">[local copy]</a>.
%F A091315 If b(n) is the (n+1)th term in A061684, then a(n) = (1/n)*Sum_{d|n}mu(d)b(n/d).
%e A091315 The sequence A061684 begins 1,1,5,64,1613, so a(3)=(b(3)-b(1))/3=21.
%Y A091315 Cf. A061684.
%K A091315 nonn
%O A091315 1,2
%A A091315 _Thomas Ward_, Feb 24 2004
%E A091315 Name clarified by _Michel Marcus_, May 14 2015