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 A283470 #22 Feb 24 2018 07:49:13 %S A283470 1,1,0,0,3,0,0,0,1,0,7,7,0,0,0,0,1,0,3,2,2,1,14,14,15,15,15,0,0,0,0,0, %T A283470 1,0,3,2,5,5,6,7,4,4,5,4,4,3,3,3,2,29,29,30,30,30,31,31,31,31,0,0,0,0, %U A283470 0,0,1,0,3,2,5,4,4,7,4,5,10,10,11,10,9,9,14,15,15,14,14,14,13,10,11,11,10,9,9,6,6,6,7,6,6,5,5,5,4,4,4,4,3 %N A283470 a(n) = A004001(A004001(n-1)) XOR A004001(n-A004001(n-1)), a(1) = a(2) = 1. %H A283470 Antti Karttunen, <a href="/A283470/b283470.txt">Table of n, a(n) for n = 1..32768</a> %F A283470 a(n) = A004001(A004001(n-1)) XOR A004001(A080677(n-1)), where XOR is bitwise-xor (A003987) %F A283470 Other identities. For all n >= 1: %F A283470 a(n) = A283469(n) - A283472(n). %F A283470 A004001(n) = a(n) + 2*A283472(n). %t A283470 a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; Table[BitXor[a[#], a[n - #]] &@ a[n - 1] + Boole[n <= 2], {n, 107}] (* _Michael De Vlieger_, Mar 18 2017, after _Robert G. Wilson v_ at A004001 *) %o A283470 (Scheme) %o A283470 (define (A283470 n) (if (<= n 2) 1 (A003987bi (A004001 (A004001 (- n 1))) (A004001 (- n (A004001 (- n 1))))))) %o A283470 ;; A003987bi implements bitwise-XOR (see A003987). Code for A004001 given under that entry. %Y A283470 Cf. A003987, A080677, A283468, A283469, A283472, A283471 (positions of zeros), A283473 (positions where coincides with A004001). %Y A283470 Cf. also A283677. %K A283470 nonn %O A283470 1,5 %A A283470 _Antti Karttunen_, Mar 18 2017 %E A283470 Erroneous b-file replaced by a correct one - _Antti Karttunen_, Feb 24 2018