%I
%S 0,0,0,2,0,2,9,54,0,30,15376,12664,14304,4096,3187
%N Triangle: T(n,k), k<=n: groupoids with a nontrivial symmetry with n elements and k idempotents.
%H <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a>
%F Difference of A038018 and A038019.
%Y Cf. A001329, A030248, A030251, A030271.
%K nonn,tabl
%O 0,4
%A _Christian G. Bower_, May 15 1998
