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 A285759 #8 Apr 26 2017 22:42:57 %S A285759 1,1,1,2,2,3,3,4,5,5,5,6,6,7,8,8,9,9,10,10,10,11,11,12,13,13,14,14,15, %T A285759 15,16,17,17,17,18,18,19,19,20,20,20,21,21,22,23,23,24,24,25,25,26,27, %U A285759 27,27,28,28,29,29,30,31,31,32,32,33 %N A285759 a(n) = a(n - 1 - a(n - 1)) + a(n - 1 - a(n - 4)), with a(1) = 1, a(2) = 1, a(3) = 1, a(4) = 2. %C A285759 The sequence a(n) is monotonic, with successive terms increasing by 0 or 1. So the sequence hits every positive integer. %H A285759 Nathan Fox, <a href="/A285759/b285759.txt">Table of n, a(n) for n = 1..10000</a> %H A285759 A. Isgur, R. Lech, S. Moore, S. Tanny, Y. Verberne, and Y. Zhang, <a href="http://dx.doi.org/10.1137/15M1040505">Constructing New Families of Nested Recursions with Slow Solutions</a>, SIAM J. Discrete Math., 30(2), 2016, 1128-1147. (20 pages); DOI:10.1137/15M1040505 %p A285759 A285759:=proc(n) option remember: if n <= 0 then 0: elif n = 1 then 1: elif n = 2 then 1: elif n = 3 then 1: elif n = 4 then 2: else A285759(n-1-A285759(n-1)) + A285759(n-1-A285759(n-4)): fi: end: %Y A285759 Cf. A005185, A063882, A285757, A285758, A285760, A285761, A285762. %K A285759 nonn %O A285759 1,4 %A A285759 _Nathan Fox_, Apr 25 2017