The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #5 Feb 22 2016 13:01:39
%S 2,6,84,43918
%N Size of free Kleene algebra on n generators.
%D J. Berman and P. Koehler, Cardinalities of finite distributive lattices, Mitteilungen aus dem Mathematischen Seminar Giessen, 121 (1976), 103-124.
%H J. Berman and P. Koehler, <a href="/A006356/a006356.pdf">Cardinalities of finite distributive lattices</a>, Mitteilungen aus dem Mathematischen Seminar Giessen, 121 (1976), 103-124. [Annotated scanned copy]
%K nonn,more
%O 0,1
%A _N. J. A. Sloane_, Feb 22 2016