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a(n) = A004001(A004001(n-1)) - A004001(n-A004001(n-1)), a(1) = a(2) = 1.
4

%I #13 Mar 19 2017 01:08:33

%S 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 -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 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 a(n) = A004001(A004001(n-1)) - A004001(n-A004001(n-1)), a(1) = a(2) = 1.

%C The only negative terms seem to be -1's, occurring as a(1+(2^n)), for n >= 2.

%H Antti Karttunen, <a href="/A283468/b283468.txt">Table of n, a(n) for n = 1..16384</a>

%F a(1) = a(2) = 1; for n > 2, a(n) = A004001(A004001(n-1)) - A004001(A080677(n-1)).

%t 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 (Scheme)

%o (define (A283468 n) (if (<= n 2) 1 (- (A004001 (A004001 (- n 1))) (A004001 (- n (A004001 (- n 1)))))))

%o ;; Code for A004001 given under that entry.

%Y Cf. A004001, A080677, A283471 (positions of zeros), A283469, A283470, A283472.

%Y Cf. also A283655.

%K sign

%O 1,20

%A _Antti Karttunen_, Mar 18 2017