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 A006763 M5232 #25 Sep 22 2019 07:17:31
%S A006763 0,0,0,32,348,2836,21225,154741,1123143,8185403,60088748,444688325,
%T A006763 3317057654,24925158492,188543716451,1434760675947,10976610064899,
%U A006763 84379534826376,651441493579872
%N A006763 Number of fixed properly-3-dimensional polyominoes with n cells.
%D A006763 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006763 W. F. Lunnon, <a href="http://dx.doi.org/10.1093/comjnl/18.4.366">Counting multidimensional polyominoes</a>. Computer Journal 18 (1975), no. 4, pp. 366-367.
%F A006763 a(n) = A001931(n) - 3 * (A001168(n) - 1) for n > 1. - _Sean A. Irvine_, Jul 27 2017
%t A006763 A001931 = Cases[Import["https://oeis.org/A001931/b001931.txt", "Table"], {_, _}][[All, 2]];
%t A006763 A001168 = Cases[Import["https://oeis.org/A001168/b001168.txt", "Table"], {_, _}][[All, 2]];
%t A006763 a[n_] := If[n == 1, 0, A001931[[n]] - 3 (A001168[[n]] - 1)];
%t A006763 a /@ Range[1, 19] (* _Jean-François Alcover_, Sep 22 2019 *)
%Y A006763 A column of A195739.
%K A006763 nonn,more
%O A006763 1,4
%A A006763 _N. J. A. Sloane_
%E A006763 More terms from _Jean-François Alcover_, Sep 22 2019