A272478 Primes with a prime number of binary digits, and with a prime number of 1's and a prime number of 0's.
17, 19, 79, 103, 107, 109, 5119, 6079, 6911, 7039, 7103, 7151, 7159, 7919, 7927, 7933, 8059, 8111, 8123, 8167, 8171, 8179, 442367, 458239, 458719, 458747, 487423, 491503, 499711, 507839, 507901, 515839, 516091, 520063, 523007, 523261, 523519, 523759, 523771, 523903, 524219, 524221, 524269
Offset: 1
Examples
a(3) = 79, its binary representation is 1001111 with (prime) 7 digits, (prime) 5 1's and (prime) 2 0's.
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..10859
- Michel Marcus, 3 primes
Programs
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Mathematica
Select[Table[Prime[j],{j,1,120000}],PrimeQ[Total@IntegerDigits[#,2]]&&PrimeQ[Length@IntegerDigits[#,2]]&&PrimeQ[(Length@IntegerDigits[#,2]-Total@IntegerDigits[#,2])]&] Select[Prime@ Range[10^5], And[PrimeQ@ Total@ #, PrimeQ@ First@ #, PrimeQ@ Last@ #] &@ DigitCount[#, 2] &] (* Michael De Vlieger, May 01 2016 *)
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PARI
isok(n) = isprime(n) && isprime(#binary(n)) && isprime(hammingweight(n)) && isprime(#binary(n) - hammingweight(n)); \\ Michel Marcus, May 01 2016
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Python
from sympy import isprime, nextprime from itertools import combinations, islice def agen(): # generator of terms p = 2 while True: p = nextprime(p) if not isprime(p+2): continue if isprime(t:=(1<<(p+1))+1): yield t b = (1<<(p+2))-1 for i, j in combinations(range(p), 2): if isprime(t:=b-(1<<(p-i))-(1<<(p-j))): yield t print(list(islice(agen(), 43))) # Michael S. Branicky, Dec 27 2023
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