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 A080606 #12 Apr 04 2015 02:40:28
%S A080606 2,2,4,4,6,6,6,6,8,8,8,8,10,10,10,10,10,10,12,12,12,12,12,12,14,14,14,
%T A080606 14,14,14,16,16,16,16,16,16,18,18,18,18,18,18,18,18,20,20,20,20,20,20,
%U A080606 20,20,22,22,22,22,22,22,22,22,24,24,24,24,24,24,24,24,26,26,26,26,26
%N A080606 Golomb's sequence using even integers.
%H A080606 Ivan Neretin, <a href="/A080606/b080606.txt">Table of n, a(n) for n = 1..10000</a>
%F A080606 a(n) is asymptotic to tau^(2-tau)*(2n)^(tau-1) and more precisely it seems that a(n) = round(tau^(2-tau)*(2n)^(tau-1)) +(-1, +0 or +1) where tau is the golden ratio.
%e A080606 Read 2,2,4,4,6,6,6,6,8,8,8,8,10,10,10,10,10,10 as (2,2),(4,4),(6,6,6,6),(8,8,8,8),(10,10,10,10,10,10) count occurrences between 2 parentheses, gives 2,2,4,4,6,... which is the sequence itself.
%t A080606 a = {2, 2}; Do[a = Join[a, Array[2i&, a[[i]]]], {i, 2, 13}]; a (* _Ivan Neretin_, Apr 03 2015 *)
%Y A080606 Cf. A001462, A080605, A080607.
%K A080606 nonn
%O A080606 1,1
%A A080606 _Benoit Cloitre_, Feb 25 2003