A281014 Numbers with both prime number of 0's and prime number of 1's in their binary reflected Gray code representation.

8, 12, 14, 16, 17, 19, 23, 24, 25, 27, 28, 29, 30, 33, 35, 39, 47, 49, 51, 55, 57, 59, 61, 64, 69, 73, 75, 77, 81, 83, 87, 89, 91, 93, 96, 101, 105, 107, 109, 112, 117, 120, 124, 126, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147

Offset

1,1

Comments

This sequence is the intersection of A280998 and A280999.

Links

Indranil Ghosh, Table of n, a(n) for n = 1..10000

Wikipedia, Gray code.

Example

27 is in the sequence as it is present in both the sequences A280998 and A280999.

Mathematica

Select[Range[150], And @@ PrimeQ[DigitCount[BitXor[#, Floor[#/2]], 2]] &] (* Amiram Eldar, May 01 2021 *)

Prog

(PARI) is(n)=isprime(logint(n, 2)-hammingweight(bitxor(n, n>>1))+1) && isprime(hammingweight(bitxor(n, n>>1))) \\ Charles R Greathouse IV, Jan 13 2017

Crossrefs

Cf. A014550, A280998, A280999.

Sequence in context: A225533 A143845 A270888 * A048868 A244723 A106669

Adjacent sequences: A281011 A281012 A281013 * A281015 A281016 A281017

Keyword

nonn,base,easy

Author

Indranil Ghosh, Jan 13 2017

Status

approved