OFFSET
1,1
COMMENTS
Cf. A096915
EXAMPLE
a(4) = 373 because 4373 is prime, while 4191, 4313, 4353 are all composite.
PROG
(Python)
from sympy import isprime, nextprime
def ispal(n): s = str(n); return s == s[::-1]
def aupto(lim):
n, p, alst = 1, 2, []
while p <= lim:
if ispal(p) and isprime(int(str(n)+str(p))): n, alst = n + 1, alst + [p]
p = nextprime(p)
return alst
print(aupto(1463641)) # Michael S. Branicky, Mar 11 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Mar 30 2005
STATUS
approved