%I #10 Jan 17 2019 16:11:12

%S 0,0,1,6,33,227,2235,31558,1668992

%N Number of monoids of order n that are not groups.

%F a(n) = A058129(n) - A000001(n).

%Y Cf. A058129, A000001.

%K nonn,more

%O 0,4

%A _Steve Szabo_, Jan 07 2019