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Primes with odd number of 1's in binary expansion such that next prime also has odd number of 1's.
1

%I #8 Mar 31 2012 13:22:15

%S 7,11,31,37,59,61,73,103,107,127,131,151,167,173,179,181,191,199,211,

%T 223,227,229,233,239,241,409,419,421,431,433,439,487,491,557,563,577,

%U 601,607,613,631,647,653,659,701,709,719,727,757,761,823,827,911,919

%N Primes with odd number of 1's in binary expansion such that next prime also has odd number of 1's.

%t c[ n_ ] := OddQ[ Count[ IntegerDigits[ n, 2 ], 1 ]]; Map[ Prime, Select[ Range[ 200 ], c[ Prime[ # ]]&&c[ Prime[ #+1 ]]& ]]

%K nonn

%O 0,1

%A _N. J. A. Sloane_.

%E More terms from _Erich Friedman_.