This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A006349 M3834 #12 Jul 08 2025 16:47:23 %S A006349 1,5,13,45,121,413,1261,4221,13801,46365,155497,527613,1792805, %T A006349 6126293,20986153,72121853,248396793,857416949,2964896877,10269596445, %U A006349 35622421561,123728022269,430254861945,1497796774077,5219231003621 %N A006349 Related to series-parallel networks. %D A006349 Z. A. Lomnicki, Two-terminal series-parallel networks, Adv. Appl. Prob., 4 (1972), 109-150. %D A006349 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %F A006349 A058352(n) + n*A000084(n). %Y A006349 Cf. A000084, A006350, A058351, A058352, A058353, A000669. %K A006349 nonn %O A006349 1,2 %A A006349 _N. J. A. Sloane_