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 A283896 #4 Mar 19 2017 19:26:06 %S A283896 91,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180, %T A283896 2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2, %U A283896 180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180,2,180 %N A283896 Relative of Hofstadter Q-sequence: a(-88) = 89, a(-87) = 2; thereafter a(n) = a(n-a(n-1)) + a(n-a(n-2)). %C A283896 In calculating terms of this sequence, use the convention that a(n)=0 for n<=-89. %C A283896 Sequences like this are more naturally considered with the first nonzero term in position 1. But this sequence would then begin with 89 terms consisting entirely of alternating 2 and 89. %C A283896 This sequence has exactly 2467 terms, since a(2467)=0 and computing a(2468) would refer to itself. %H A283896 Nathan Fox, <a href="/A283896/b283896.txt">Table of n, a(n) for n = 1..2467</a> %p A283896 A283896:=proc(n) option remember: if n <= -89 then 0: elif n = -88 then 89: elif n = -87 then 2: else A283896(n-A283896(n-1)) + A283896(n-A283896(n-2)): fi: end: %Y A283896 Cf. A005185, A278066, A278067, A278068, A283893, A283894, A283895, A283897. %K A283896 nonn,fini,full %O A283896 1,1 %A A283896 _Nathan Fox_, Mar 19 2017