OFFSET
1,1
COMMENTS
If one of the digits is 0, it is read "zero zeros" and the term is thus omitted from the concatenation.
There are infinitely many numbers in this sequence. Any number can have an infinite number of 0's in its decimal expansion.
EXAMPLE
For n = 53, this becomes 5 fives and then 3 threes = 55555333. Since 55555333 is prime, 53 is a member of this sequence.
PROG
(Python)
import sympy
from sympy import isprime
def a():
..for n in range(1, 10**4):
....num = ''
....lst = list(str(n))
....for i in lst:
......num += i*int(i)
....if isprime(int(num)):
......print(n)
a()
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek Orr, Jun 01 2014
STATUS
approved