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 A058353 #3 Mar 30 2012 16:48:55 %S A058353 1,4,12,40,120,396,1260,4176,13788,46240,155496,527160,1792804, %T A058353 6125028,20986020,72117632,248396792,857402748,2964896876,10269550040, %U A058353 35622420288,123727866768,430254861944,1497796242288,5219231003500 %N A058353 n*A000084(n). %D A058353 Z. A. Lomnicki, Two-terminal series-parallel networks, Adv. Appl. Prob., 4 (1972), 109-150. %Y A058353 Cf. A000084, A006349, A006350, A058351, A058352, A000669. %K A058353 nonn %O A058353 1,2 %A A058353 _N. J. A. Sloane_, Dec 16 2000