The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #2 Mar 30 2012 18:40:51
%S 1,2,4,10,41,343,6327,249995,20536020,3445474030,1169394086932,
%T 798731069436512,1094825607339329108,3006942191342795594938,
%U 16533858553282474307626008,181924651566316766693192987410
%N Partial sums of A003087.
%C Partial sums of number of acyclic digraphs with n unlabeled nodes; equivalently partial sums of the number of equivalence classes of n X n real (0,1)-matrices with all eigenvalues positive, up to conjugation by permutations. The subsequence of primes in this partial sum begins: 2, 41, no more through a(18).
%F a(n) = SUM[i=0..n] A003087(i).
%Y Cf. A003087, A003024.
%K nonn
%O 0,2
%A _Jonathan Vos Post_, Mar 09 2010