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 A333018 #24 Feb 15 2021 01:56:58
%S A333018 1,1,1,3,10,44,249,1513,9992,68305,480748,3450793,25186583
%N A333018 Number of free heptagonal polyforms with n cells on the heptagonal tiling of the hyperbolic plane.
%C A333018 The heptagonal tiling is represented by Schläfli symbol {7,3}.
%C A333018 This sequence is to A259352 what A000228 is to A108070.
%C A333018 This sequence is computed from via program by _Christian Sievers_ in the Code Golf Stack Exchange link.
%H A333018 Code Golf Stack Exchange, <a href="https://codegolf.stackexchange.com/a/200295/53884">Impress Donald Knuth by counting polyominoes on the hyperbolic plane</a>
%H A333018 Wikipedia, <a href="https://en.wikipedia.org/wiki/Heptagonal_tiling">Heptagonal tiling</a>
%H A333018 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polyform">Polyform</a>
%o A333018 Several programs are available via the Code Golf link.
%Y A333018 Analogs with different Schläfli symbols are A000105 ({4,4}), A000207 ({3,oo}), A000228 ({6,3}), A000577 ({3,6}), A005036 ({4,oo}), A119611 ({4,5}), A330659 ({3,7}), and A332930 ({4,6}).
%Y A333018 Cf. A108070, A259352.
%K A333018 nonn,more,hard
%O A333018 0,4
%A A333018 _Peter Kagey_, Mar 05 2020
%E A333018 a(9)-a(12) from _Ed Wynn_, Feb 14 2021