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A081092
Primes having in binary representation a prime number of 1's.
14
3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 47, 59, 61, 67, 73, 79, 97, 103, 107, 109, 127, 131, 137, 151, 157, 167, 173, 179, 181, 191, 193, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 271, 283, 307, 313, 331, 367, 379, 397, 409, 419, 421, 431, 433, 439, 443
OFFSET
1,1
COMMENTS
Same as primes with prime binary digit sum.
Primes with prime decimal digit sum areA046704.
Sum_{a(n) < x} 1/a(n) is asymptotic to log(log(log(x))) as x -> infinity; see Harman (2012). Thus the sequence is infinite. -Jonathan Sondow,Jun 09 2012
A049084(A000120(a(n))) > 0;A081091,A000215andA081093are subsequences.
LINKS
G. Harman,Counting Primes whose Sum of Digits is Prime,J. Integer Seq., 15 (2012), Article 12.2.2.
EXAMPLE
15th prime = 47 = '101111' with five 1's, therefore 47 is in the sequence.
MAPLE
q:= n-> isprime(n) and isprime(add(i, i=Bits[Split](n))):
select(q, [$1..500])[]; #Alois P. Heinz,Sep 28 2023
MATHEMATICA
Clear[BinSumOddQ]; BinSumPrimeQ[a_]:=Module[{i, s=0}, s=0; For[i=1, i<=Length[IntegerDigits[a, 2]], s+=Extract[IntegerDigits[a, 2], i]; i++ ]; PrimeQ[s]]; lst={}; Do[p=Prime[n]; If[BinSumPrimeQ[p], AppendTo[lst, p]], {n, 4!}]; lst (*Vladimir Joseph Stephan Orlovsky,Apr 06 2009 *)
Select[Prime[Range[100]], PrimeQ[Apply[Plus, IntegerDigits[#, 2]]] &] (*Jonathan Sondow,Jun 09 2012 *)
PROG
(Haskell)
a081092 n = a081092_list!! (n-1)
a081092_list = filter ((== 1). a010051') a052294_list
--Reinhard Zumkeller,Nov 16 2012
(PARI) lista(nn) = {forprime(p=2, nn, if (isprime(hammingweight(p)), print1(p, "," )); ); } \\Michel Marcus,Jan 16 2015
(Python)
from sympy import isprime
def ok(n): return isprime(n.bit_count()) and isprime(n)
print([k for k in range(444) if ok(k)]) #Michael S. Branicky,Dec 27 2023
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller,Mar 05 2003
STATUS
approved