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 A000645 M1209 N0467 #19 Feb 01 2022 01:07:09
%S A000645 1,2,4,10,25,64,166,437,1157,3087,8276,22287,60230,163284,443820,
%T A000645 1209155,3300890,9027337,24727437,67829684,186302693,512301120,
%U A000645 1410237805,3885803531,10716571591,29579231200,81704634803,225845362116
%N A000645 Number of alkyls X^{II} C_n H_{2n+1} Y with n carbon atoms.
%D A000645 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A000645 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A000645 G. Polya, <a href="http://dx.doi.org/10.1524/zkri.1936.93.1.415">Algebraische Berechnung der Anzahl der Isomeren einiger organischer Verbindungen</a>, Zeit. f. Kristall., 93 (1936), 415-443; line 11 of Table I.
%H A000645 G. Polya, <a href="/A000598/a000598_3.pdf">Algebraische Berechnung der Anzahl der Isomeren einiger organischer Verbindungen</a>, Zeit. f. Kristall., 93 (1936), 415-443; Table 1, line 11. (Annotated scanned copy)
%F A000645 G.f.: A(x) = A000598(x)/(1-A000642(x)).
%K A000645 nonn,easy
%O A000645 0,2
%A A000645 _N. J. A. Sloane_