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%I
%S 0,0,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,
%T 0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,
%U 0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0
%N Binary sequence identifying the twin primes (characteristic function of twin primes: 1 if n is a twin prime else 0).
%C Similar to prime binary digit sequence A010051.
%C In decimal notation A164292=0.1646823906345389353962381...
%C See also A164293 (similar to prime decimal sequence A051006).
%C a(A001097(n))=1; a(A001359(n))=1; a(A006512(n))=1. [From _Reinhard Zumkeller_, Mar 29 2010]
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a> [From _Reinhard Zumkeller_, Mar 29 2010]
%Y Cf. A129950, A010051, A164293, A051006.
%Y a(n) = A057427(A010051(n)*(A010051(n-2)+A010051(n+2))), n>2. [From _Reinhard Zumkeller_, Mar 29 2010]
%K nonn
%O 1,1
%A Carlos Alves (cjsalves(AT)gmail.com), Aug 12 2009
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