%I A000163 M1852 N0732
%S A000163 2,8,34,136,538,2080,7970,30224,113874,426520,1590338,5906640,21866794,
%T A000163 80725280,297292610,1092539736,4007553922,14675748416,53663197698,
%U A000163 195962433328,714734393378,2603994002280,9477643739746,34463730424720
%N A000163 Series-parallel numbers.
%D A000163 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000163 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000163 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 
               142.
%F A000163 G.f.: 2*(1+S)/(1-S)^3, where S = g.f. for A000084. [From Sean A. Irvine 
               (sairvin(AT)xtra.co.nz), Oct 14 2009]
%Y A000163 Sequence in context: A005040 A026577 A111643 this_sequence A117616 A014445 
               A113440
%Y A000163 Adjacent sequences: A000160 A000161 A000162 this_sequence A000164 A000165 
               A000166
%K A000163 nonn
%O A000163 2,1
%A A000163 N. J. A. Sloane (njas(AT)research.att.com).
%E A000163 More terms from Sean A. Irvine (sairvin(AT)xtra.co.nz), Oct 14 2009