The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A272478 Primes with a prime number of binary digits, and with a prime number of 1's and a prime number of 0's. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If the sum of primes p and q is a prime r, then one of p and q must be 2. - N. J. A. Sloane, May 01 2016
LINKS
Michel Marcus, 3 primes
EXAMPLE
a(3) = 79, its binary representation is 1001111 with (prime) 7 digits, (prime) 5 1's and (prime) 2 0's.
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 *)
PROG
(PARI) isok(n) = isprime(n) && isprime(#binary(n)) && isprime(hammingweight(n)) && isprime(#binary(n) - hammingweight(n)); \\ Michel Marcus, May 01 2016
(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
CROSSREFS
Sequence in context: A226681 A005808 A180559 * A028489 A210242 A165320
KEYWORD
nonn,base
AUTHOR
Andres Cicuttin, May 01 2016
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 3 23:31 EDT 2024. Contains 373088 sequences. (Running on oeis4.)