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 A293501 #11 Jun 02 2025 12:22:42 %S A293501 3,40,318,1974,10603,51894,238413,1047440,4454826,18496217,75416600, %T A293501 303287250,1206781482,4762466651,18674965709,72866587238,283217927396, %U A293501 1097537249485,4243554109115,16379413110981,63142882465324,243203630272390 %N A293501 Number of unlabeled semiorders on n points and having dimension 3. %H A293501 Mitchel T. Keller, Stephen J. Young, <a href="https://arxiv.org/abs/1801.00501">Hereditary Semiorders and Enumeration of Semiorders by Dimension</a>, arXiv:1801.00501 [math.CO], 2018. %F A293501 a(n) = A000108(n) - A293498(n). %Y A293501 Cf. A000108, A293498. %K A293501 nonn %O A293501 7,1 %A A293501 _Mitchel T. Keller_, Oct 10 2017