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 A081651 #6 Jul 12 2015 20:35:25 %S A081651 1,1,1,2,2,2,2,3,3,4,5,10,86,1499263005586576 %N A081651 a(n) = floor((3/2)^^n), where x^^n is the power tower x^(x^(...^x)) with n x's. %t A081651 f[n_] := (3/2)^n; Floor[ NestList[f, 3/2, 12]] %Y A081651 Cf. A014221. %K A081651 nonn %O A081651 0,4 %A A081651 _Robert G. Wilson v_, Mar 26 2003 %E A081651 New definition from _Benoit Jubin_, Jul 22 2008 %E A081651 Inserted a missing 1 at the beginning, _Benoit Jubin_, Aug 04 2008