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 A079191 #6 Jul 10 2011 18:42:31 %S A079191 1,4,2,2,8,34,952,2,1,14,6,211,283,13570,31843561 %N A079191 Number of isomorphism classes of anti-commutative closed binary operations on a set of order n, listed by class size. %C A079191 A079188(n)+A079191(n)=A079171(n). %C A079191 Elements per row: 1,2,4,8,16,30,... (given by A027423, number of positive divisors of n!) %C A079191 First four rows: 1; 4,2; 2,8,34,952; 2,1,14,6,211,283,13570,31843561 %C A079191 A079189(x) is equal to the sum of the products of each element in row x of this sequence and the corresponding element of A079210. %C A079191 The sum of each row x of this sequence is given by A079190(x). %H A079191 C. van den Bosch, <a href="http://cosmos.ucc.ie/~cjvdb1/html/binops.shtml">Closed binary operations on small sets</a> %H A079191 <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a> %Y A079191 Cf. A079188, A079189, A079190. %K A079191 nonn,tabf %O A079191 1,2 %A A079191 Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003