%I
%S 3,2,7,5,13,11,31,29,17,19,23,61,59,53,37,47,41,43,127,113,97,103,101,
%T 109,107,67,71,79,73,89,83,251,241,227,229,239,233,193,199,197,223,
%U 211,131,137,139,157,151,149,191,179,181,163,167,173,509,499,503,487,491,449,463,461
%N Primes as they appear in A006068.
%C a(n) is the ith prime (as it appears in A000040) for i = 2, 1, 4, 3, 6, 5, 9, 10, 11, 8, 7, 15, 17, 18, 16, 14, etc.
%t f[n_] := BitXor @@ Table[ Floor[n/2^m], {m, 0, Floor[Log2@ n]}]; Select[ Array[f, 300], PrimeQ]
%o (PARI) grayinto(n) = my(B=n); for(k=1, log(n+1)\log(2), B=bitxor(B, n\2^k)); B;
%o lista(nn) = for (n=1, nn, if (isprime(p=grayinto(n)), print1(p, ", "))); \\ _Michel Marcus_, Oct 10 2017
%Y Cf. A006068, A292203, A292205.
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Sep 11 2017
