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 A296195 #11 Dec 14 2017 09:20:59 %S A296195 1,1,3,10,39,160,691,3081,14095,65757,311695,1496833,7267009 %N A296195 Number of disjoint covering systems of cardinality n. %C A296195 A disjoint covering system or DCS (also called "exact covering system" or ECS) is a system of n congruences such that every integer belongs to exactly one of the congruences. %C A296195 This sequence agrees with A050385 on the first 12 terms, but differs at a(13). %D A296195 S. Porubsky and J. Schönheim, Covering systems of Paul Erdös: past, present and future, in Paul Erdös and his Mathematics, Vol. I, Bolyai Society Mathematical Studies 11 (2002), 581-627. %H A296195 I. P. Goulden, L. B. Richmond, and J. Shallit, <a href="https://arxiv.org/abs/1711.04109v3">Natural exact covering systems and the reversion of the Möbius series</a>, arXiv:1711.04109v3 [math.NT], revision of Dec 12 2017 %e A296195 For n = 3 the a(3) = 3 DCS are %e A296195 (i) x == 0 (mod 3), x == 1 (mod 3), x == 2 (mod 3) %e A296195 (ii) x == 0 (mod 2), x == 1 (mod 4), x == 3 (mod 4) %e A296195 (iii) x == 1 (mod 2), x == 0 (mod 4), x == 2 (mod 4) %Y A296195 Cf. A050385, which counts a subset of the DCS called "natural exact covering systems". %K A296195 nonn,more %O A296195 1,3 %A A296195 _Jeffrey Shallit_, Dec 07 2017