Search: id:A000137 Results 1-1 of 1 results found. %I A000137 M1625 N0636 %S A000137 1,2,6,18,58,186,614,2034,6818,22970,77858,264970,905294,3102434, %T A000137 10661370,36722642,126752218,438294018,1518032598,5265341314,18286911130, %U A000137 63586988434,221342104842,771235606050,2689688538646,9388096331642 %N A000137 Series-parallel numbers. %D A000137 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A000137 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A000137 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 142. %F A000137 G.f.: (1+S)/(1-S), where S = g.f. for A000084. %Y A000137 Cf. A036654, A036655, A058756, A000084. %Y A000137 Sequence in context: A148458 A148459 A081057 this_sequence A151282 A157004 A085139 %Y A000137 Adjacent sequences: A000134 A000135 A000136 this_sequence A000138 A000139 A000140 %K A000137 nonn %O A000137 1,2 %A A000137 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.001 seconds