OFFSET
1,1
COMMENTS
a(351) has 1002 digits. - Michael S. Branicky, Mar 19 2024
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..350
PROG
(Python)
from sympy import isprime
from itertools import count
def a(n):
prefix = int("".join(map(str, (2*i+1 for i in range(n)))))
if isprime(prefix): return prefix
for extra in count(1):
prefix *= 10
for i in range(10**extra):
t = prefix + i
if isprime(t): return t
print([a(n) for n in range(1, 17)]) # Michael S. Branicky, Mar 19 2024
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Mar 09 2002
EXTENSIONS
More terms from Benoit Cloitre, Mar 10 2002
a(10) corrected by Jayanta Basu, Aug 08 2013
a(6)-a(8) and a(13) corrected and more terms from Sean A. Irvine, Mar 17 2024
STATUS
approved