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A117964
a(n) = A117963(n) mod 2.
2
1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
0,1
COMMENTS
a(3n+2) = 0, a(3n) = a(3n+1). a(3n) may be equal to A088917(n).
FORMULA
a(n)=sum{k=0..floor(n/2), L(C(n-k,k)/3)} mod 2 where L(j/p) is the Legendre symbol of j and p.
a(2*A081601(n)) = a(1+2*A081601(n)) = 1. [Conjectured, also these two formulas together seem to give the positions of all 1's] - Antti Karttunen, Jan 01 2023
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 05 2006
STATUS
approved