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 A283655 #16 Mar 14 2017 00:26:54 %S A283655 0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,1,2,2,2,2,2,2,1,1,1,0,0,0,0,0,0,1,2, %T A283655 3,3,3,3,4,4,4,4,4,4,3,3,3,3,3,3,2,2,2,1,1,1,1,0,0,0,0,0,0,0,1,2,3,4, %U A283655 4,4,4,5,6,6,6,6,7,7,7,7,7,7,6,6,6,6,7,7,7,7,7 %N A283655 a(n) = b(b(n+1)) - b(n-b(n)+1) where b(n) = A004001(n). %H A283655 Altug Alkan, <a href="/A283655/b283655.txt">Table of n, a(n) for n = 1..10000</a> %H A283655 Altug Alkan, <a href="/A283655/a283655.png">Illustration of A283655</a> %e A283655 a(1) = 0 since a(1) = A004001(A004001(2)) - A004001(1-A004001(1)+1) = 1 - 1 = 0. %t A283655 b[1] = 1; b[2] = 1; b[n_] := b[n] = b[b[n - 1]] + b[n - b[n - 1]]; a[n_] := b[b[n + 1]] - b[n - b[n] + 1]; Array[a, 100] (* _Robert G. Wilson v_, Mar 13 2017 *) %o A283655 (PARI) a=vector(1001); a[1]=a[2]=1; for(n=3, #a, a[n]=a[a[n-1]]+a[n-a[n-1]]); va = vector(1000, n, a[a[n+1]]-a[n+1-a[n]]) %Y A283655 Cf. A004001, A004074, A233270, A249071. %K A283655 nonn %O A283655 1,18 %A A283655 _Altug Alkan_, Mar 13 2017