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A281014 Numbers with both prime number of 0's and prime number of 1's in their binary reflected Gray code representation. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This sequence is the intersection of A280998 and A280999.
LINKS
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
Sequence in context: A225533 A143845 A270888 * A048868 A244723 A106669
KEYWORD
nonn,base,easy
AUTHOR
Indranil Ghosh, Jan 13 2017
STATUS
approved

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Last modified March 29 08:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)