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 A074025 #25 Jan 17 2024 15:04:02 %S A074025 1,4,8,16 %N A074025 Numbers k such that a triplewhist tournament TWh(k) exists. %C A074025 The present state of knowledge, quoting from Ge (2007), is that a TWh(k) exists iff k == 0 or 1 (mod 4), except for k = 5, 9, 12, 13 and possibly 17. %C A074025 After 16, the sequence continues 17?, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 56, 57, ... %H A074025 G. Ge and C. W. H. Lam, <a href="https://doi.org/10.1016/S0097-3165(02)00018-3">Some new triplewhist tournaments TWh(v)</a>, J. Combinat. Theory, A101 (2003), 153-159. %H A074025 Gennian Ge, <a href="https://doi.org/10.1016/j.jcta.2007.01.012">Triplewhist tournaments with the three person property</a>, J. Combinat. Theory, A114 (2007), 1438-1455. %H A074025 Harri Haanpää and Petteri Kaski, <a href="http://lib.tkk.fi/Diss/2004/isbn9512269422/article3.pdf">The near resolvable 2-(13,4,3) designs and thirteen-player whist tournaments</a> [shows that no TWh(13) exists] %K A074025 nonn,more,bref,nice %O A074025 1,2 %A A074025 _N. J. A. Sloane_, Oct 16 2003 %E A074025 Of course this entry is much too short. But I have included it in the hope that this will encourage someone to settle the question of whether a(5) is 17 or 20 - i.e., does a TWh(17) exist? %E A074025 Link supplied by _Jon E. Schoenfield_, Aug 01 2006 %E A074025 Edited by _Andrey Zabolotskiy_, Jan 17 2024