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 A137348 #8 Feb 02 2020 21:37:36 %S A137348 1,1,0,1,0,0,0,30,0,2520,0,0,0,37362124800,0,14311959985625702400,0,0, %T A137348 0 %N A137348 Number of Steiner quadruple systems (SQS's) of order n. %C A137348 The values are calculated by utilizing the Knuth's Algorithm X. Only the number of non-isomorphic SQS's is presented in peer-reviewed literature and scientific textbooks. The algorithm was verified to be valid by seeking STS's presented in A001201. %C A137348 n=14 calculated from "Mendelsohn and Hung: On Steiner Systems S(3,4,14) and S(4,5,15), Util. Math. Vol 1 (1972), pp. 5-95" with orbit-stabilizer theorem %C A137348 n=15 is given in "Petteri Kaski, Patric R. J. Östergård (Patric.Ostergard(AT)hut.fi) and O. Pottonen, The Steiner quadruple systems of order 16". SQS(20) is still unknown. %D A137348 Petteri Kaski, Patric R. J. Östergård (Patric.Ostergard(AT)hut.fi) and O. Pottonen, The Steiner quadruple systems of order 16 %D A137348 N. S. Mendelsohn and S. H. Y. Hung, On the Steiner Systems S(3,4,14) and S(4,5,15), Util. Math. Vol. 1, 1972, pp. 5-95 %H A137348 Vesa Linja-aho, <a href="http://www.ct.tkk.fi/~vesa/">Home Page</a>. %H A137348 Vesa Linja-aho, <a href="/A137348/a137348.txt">Python program</a> %H A137348 <a href="/index/St#Steiner">Index entries for sequences related to Steiner systems</a> %e A137348 There are 2520 SQS's on 10 points. %K A137348 hard,nonn %O A137348 1,8 %A A137348 Vesa Linja-aho (vesa.linja-aho(AT)tkk.fi), Apr 08 2008, May 13 2008