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 A283468 #13 Mar 19 2017 01:08:33
%S A283468 1,1,0,0,-1,0,0,0,-1,0,1,1,0,0,0,0,-1,0,1,2,2,1,2,2,1,1,1,0,0,0,0,0,
%T A283468 -1,0,1,2,3,3,2,3,4,4,3,4,4,3,3,3,2,3,3,2,2,2,1,1,1,1,0,0,0,0,0,0,-1,
%U A283468 0,1,2,3,4,4,3,4,5,6,6,5,6,7,7,6,7,7,6,6,6,5,6,7,7,6,7,7,6,6,6,5,6,6,5,5,5,4,4,4,4,3,4,4,3,3,3,2,2,2,2,1,1,1,1
%N A283468 a(n) = A004001(A004001(n-1)) - A004001(n-A004001(n-1)), a(1) = a(2) = 1.
%C A283468 The only negative terms seem to be -1's, occurring as a(1+(2^n)), for n >= 2.
%H A283468 Antti Karttunen, <a href="/A283468/b283468.txt">Table of n, a(n) for n = 1..16384</a>
%F A283468 a(1) = a(2) = 1; for n > 2, a(n) = A004001(A004001(n-1)) - A004001(A080677(n-1)).
%t A283468 a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; Table[a[#] - a[n - #] &@ a[n - 1] + Boole[n <= 2], {n, 120}] (* _Michael De Vlieger_, Mar 18 2017, after _Robert G. Wilson v_ at A004001 *)
%o A283468 (Scheme)
%o A283468 (define (A283468 n) (if (<= n 2) 1 (- (A004001 (A004001 (- n 1))) (A004001 (- n (A004001 (- n 1)))))))
%o A283468 ;; Code for A004001 given under that entry.
%Y A283468 Cf. A004001, A080677, A283471 (positions of zeros), A283469, A283470, A283472.
%Y A283468 Cf. also A283655.
%K A283468 sign
%O A283468 1,20
%A A283468 _Antti Karttunen_, Mar 18 2017