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%I #13 Jul 23 2023 17:00:33
%S -1,1,2,0,2,1,-1,0,-1,1,-1,0,2,1,2,0,-1,1,-1,0,2,1,-1,0,-1,1,2,0,2,1,
%T 2,0,-1,1,-1,0,2,1,-1,0,-1,1,-1,0,2,1,2,0,-1,1,2,0,2,1,-1,0,-1,1,2,0,
%U 2,1,2,0,-1,1,-1,0,2,1,-1,0,-1,1,-1
%N a(-1) = -1, a(0) = 1, a(n) = A317539(n) - 3*(n-1) for n > 0.
%F a(-1) = -1, a(1) = 2, a(4n) = 1, a(4n+2) = 0, a(8n+3) = 2, a(8n+7) = -1, a(8n+1) = a(4n+1), a(1) = 2, a(8n+5) = a(4n-1), for n >= 0.
%o (Python)
%o a = [-1,1,2]
%o print(-1,-1)
%o print(0,1)
%o print(1,2)
%o n = 2
%o while n < 128:
%o if n%4 == 0:
%o a = a+[1]
%o elif n%4 == 2:
%o a = a+[0]
%o elif n%8 == 1:
%o a = a+[a[4*(n//8)+2]]
%o elif n%8 == 3:
%o a = a+[2]
%o elif n%8 == 5:
%o a = a+[a[4*(n//8)]]
%o else: # n%8 == 7
%o a = a+[-1]
%o print(n,a[n+1])
%o n = n+1
%Y Cf. A317539.
%K sign
%O -1,3
%A _A.H.M. Smeets_, Jul 30 2018
%E Offset and NAME corrected by _R. J. Mathar_, Jun 19 2021
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