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 A073094 #12 Jun 12 2018 02:42:24
%S A073094 2,6,2,4,2,6,2,6,2,4,2,4,8,4,2,4,2,6,2,6,2,4,2,6,2,6,2,4,2,4,8,4,2,4,
%T A073094 2,4,8,4,8,6,8,4,8,4,2,4,2,4,8,4,2,4,2,6,2,6,2,4,2,6,2,6,2,4,2,4,8,4,
%U A073094 2,4,2,6,2,6,2,4,2,6,2,6,2,4,2,4,8,4,2,4,2,4,8,4,8,6,8,4,8,4,2,4,2,4,8,4,2
%N A073094 Final digit of C(2k,k) when not equal to zero.
%C A073094 Sequence contains 2,4,6,8, only.
%H A073094 Robert Israel, <a href="/A073094/b073094.txt">Table of n, a(n) for n = 1..10000</a>
%F A073094 a(n) = C(2*A037453(n), A037453) reduced modulo 10.
%p A073094 f:= proc(n) local L,r;
%p A073094 L:= convert(n,base,3);
%p A073094 r:= 2 &^ numboccur(1,L) mod 5;
%p A073094 r + 5*(r mod 2)
%p A073094 end proc:
%p A073094 map(f, [$1..200]); # _Robert Israel_, Jun 11 2018
%t A073094 Mod[#,10]&/@Table[Binomial[2n,n],{n,800}]/.(0->Nothing) (* _Harvey P. Dale_, Apr 14 2018 *)
%K A073094 easy,nonn,base
%O A073094 1,1
%A A073094 _Benoit Cloitre_, Aug 18 2002