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 A079178 #6 Jul 10 2011 18:42:30 %S A079178 0,2,6,3,10,78,3229,2,1,12,30,246,495,48427,178914959 %N A079178 Number of isomorphism classes of non-anti-associative closed binary operations on a set of order n, listed by class size. %C A079178 A079178(n)+A079181(n)=A079171(n). %C A079178 Elements per row: 1,2,4,8,16,30,... (given by A027423, number of positive divisors of n!) %C A079178 First four rows: 0; 2,6; 3,10,78,3229; 2,1,12,30,246,495,48427,178914959 %C A079178 A079176(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 A079178 The sum of each row x of this sequence is given by A079177(x). %H A079178 C. van den Bosch, <a href="http://cosmos.ucc.ie/~cjvdb1/html/binops.shtml">Closed binary operations on small sets</a> %H A079178 <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a> %Y A079178 Cf. A079176, A079177, A079179. %K A079178 nonn,tabf %O A079178 1,2 %A A079178 Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003