OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..500
MATHEMATICA
Flatten[ Table[ Select[ Sort[ FromDigits /@ Permutations[ Flatten[{3, Table[1, {n}]}]]], PrimeQ[ # ] &], {n, 0, 12}]]
PROG
(Python)
from sympy import isprime
def agen():
digits = 0
while True:
for i in range(digits+1):
t = int("1"*(digits-i) + "3" + "1"*i)
if isprime(t): yield t
digits += 1
g = agen()
print([next(g) for i in range(25)]) # Michael S. Branicky, Mar 13 2021
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov and Robert G. Wilson v, May 20 2005
STATUS
approved