cp's OEIS Frontend

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.

A058170 Triangle: Number of asymmetric semigroups of order n with k idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).

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%I A058170 #6 Mar 30 2012 17:37:12
%S A058170 1,2,1,3,7,2,10,28,33,7,82,153,261,213,37,2511,1227,2266,2989,1709,
%T A058170 263,600106,26033,24176,39176,38346,16306,2134
%N A058170 Triangle: Number of asymmetric semigroups of order n with k idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
%H A058170 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a>
%e A058170 1; 2,1; 3,7,2; 10,28,33,7; 82,153,261,213,37; ...
%Y A058170 Row sums give A058107.
%K A058170 nonn,tabl,hard
%O A058170 1,2
%A A058170 _Christian G. Bower_, Nov 19 2000