%I M2029 N0801 #20 Jan 14 2023 02:09:09
%S 0,2,12,60,292,1438,7180,36566
%N Colored series-parallel networks.
%D J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 159.
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_