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 A007599 M0455 #17 Aug 28 2016 18:23:35
%S A007599 1,0,1,1,1,1,2,3,4,5,5,5,6,7,8,9,9,9,10,11,11,11,12,13,14,15,15,15,16,
%T A007599 17,17,17,18,19,19,19,20,21,21,21,22,23,24,25,25,25,26,27,27,27,28,29,
%U A007599 29,29,30,31,31,31,32,33,33,33,34,35,35,35,36,37,37,37,38,39,39,39,40
%N A007599 a(n+1) = a(n)+a(a(a(..(n-1)..))), depth [ n/2 ].
%D A007599 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A007599 T. D. Noe, <a href="/A007599/b007599.txt">Table of n, a(n) for n = 0..1000</a>
%t A007599 a[n_Integer] := a[n] = (a[n - 1] + Nest[a, n - 2, Floor[n/2] ] ); a[0] = 1; a[1] = 0; Table[ a[n], {n, 0, 75} ]
%o A007599 (Haskell)
%o A007599 a007599 n = a007599_list !! n
%o A007599 a007599_list = 1 : f 1 1 where
%o A007599 f x m = y : f y (m + 1) where
%o A007599 y = x + (iterate a007599 (m-2)) !! (m `div` 2)
%o A007599 -- _Reinhard Zumkeller_, Jan 05 2012
%K A007599 nonn,nice,easy
%O A007599 0,7
%A A007599 _N. J. A. Sloane_, _Mira Bernstein_, _Robert G. Wilson v_