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 A022014 #21 May 13 2019 18:06:41
%S A022014 0,1,3,9,27,81,240,711,2094,6152,18012,52613,153297,445772,1293780,
%T A022014 3748820,10845935,31336532,90426198,260644262,750502831,2158961013,
%U A022014 6205225334,17820505454,51139664497,146654181925,420291420558
%N A022014 Tri-substituted alkanes of form C_n H_{2n-1} X_2 Y, or equivalently bi-substituted alkyls of form -C_n H_{2n-1} X_2 (n=1: CHXXY; n=2: CXXY-CHHH CXYH-CXHH CXXH-CYHH).
%H A022014 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a022/A022014.java">Java program</a> (github)
%H A022014 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 6 of Table I.
%H A022014 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 I, line 6. (Annotated scanned copy)
%F A022014 G.f.: (1/2) * (x*r(x)/(1-x*R(x)) * (1/(1-x*R(x))^2 + 1/(1-x^2*R(x^2))) where r(x) is the g.f. for A000598 and R(x) is the g.f. for A000642 [from Polya, p. 440]. - _Sean A. Irvine_, May 13 2019
%Y A022014 Cf. A000598, A000641, A000642.
%K A022014 nonn
%O A022014 0,3
%A A022014 _N. J. A. Sloane_, _Paul Zimmermann_