%I A004040
%S A004040 1,2,6,23,103,512,2740,15485,91245,555662,3475090,22214707,
%T A004040 144640291,956560748,6411521056,43478151737,297864793993
%N A004040 Inversion of A000257.
%F A004040 Invert: define b by 1+Sum a(n)x^n = 1/(1 - Sum b(n)x^n).
%Y A004040 Essentially the same as A022558.
%Y A004040 Sequence in context: A050389 A098746 A088929 this_sequence A022558 A005802 
               A061552
%Y A004040 Adjacent sequences: A004037 A004038 A004039 this_sequence A004041 A004042 
               A004043
%K A004040 nonn
%O A004040 0,2
%A A004040 N. J. A. Sloane (njas(AT)research.att.com).