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A120533 Primes having a prime number of digits. 3
11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Before the 20th century, this sequence would have contained the numbers 1,2,3,5,7; see A008578.
There are a total of 8527 terms for primes with 2, 3, or 5 digits, and a total of 594608 terms if primes with 7 digits are also included. - Harvey P. Dale, Nov 02 2020
LINKS
EXAMPLE
10007 is a 5-digit prime and so belongs to the sequence.
MATHEMATICA
Table[Prime[Range[PrimePi[10^(p-1)]+1, PrimePi[10^p]]], {p, Prime[Range[ 3]]}]//Flatten (* Harvey P. Dale, Nov 02 2020 *)
PROG
(PARI) g(n) = forprime(x=11, n, if(isprime(length(Str(x))), print1(x", ")))
(PARI) forprime(p=2, 5, forprime(q=10^(p-1), 10^p, print1(q", "))) \\ Charles R Greathouse IV, Oct 04 2011
(Python)
from itertools import islice
from sympy import isprime, nextprime
def agen(): # generator of terms
d = 2
while True:
yield from (i for i in range(10**(d-1)+1, 10**d, 2) if isprime(i))
d = nextprime(d)
print(list(islice(agen(), 57))) # Michael S. Branicky, Dec 27 2023
CROSSREFS
Sequence in context: A096489 A008364 A140461 * A226108 A273906 A095862
KEYWORD
base,nonn
AUTHOR
Cino Hilliard, Aug 06 2006
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 21 2007
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)