%I #19 Mar 20 2023 12:43:47
%S 0,1,1,0,0,0,1,0,1,1,0,0,0,1,0,1,0,0,0,1,0,0,1,1,0,1,0,0,0,1,0,0,0,1,
%T 1,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,1,0,1,1,0,1,0,1,0,1,0,1,
%U 1,1,1,1,0,1,0,1,1,0,1,0,0,0,0,0,0,0
%N a(n)=1 iff binary weight of n-th prime is even.
%C Characteristic function of A027700.
%H T. D. Noe, <a href="/A200244/b200244.txt">Table of n, a(n) for n = 1..1000</a>
%t Table[1 - Mod[Total[IntegerDigits[Prime[n], 2]], 2], {n, 100}] (* _T. D. Noe_, Nov 21 2011 *)
%o (Magma) [IsEven(&+Intseq(NthPrime(n),2)) select 1 else 0: n in [1..100]]; // _Bruno Berselli_, Nov 16 2011
%Y Cf. A027700, A200246.
%K nonn
%O 1
%A _N. J. A. Sloane_, Nov 15 2011