

A062351


Palindromic primes with strictly increasing digits up to the middle and then strictly decreasing.


7



2, 3, 5, 7, 11, 131, 151, 181, 191, 353, 373, 383, 787, 797, 12421, 12721, 12821, 13831, 13931, 14741, 17971, 34543, 34843, 35753, 1235321, 1245421, 1257521, 1268621, 1278721, 1456541, 1469641, 1489841, 1579751, 1589851, 3479743
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OFFSET

1,1


COMMENTS

The last term of the finite series is a(63) = 123467898764321.


LINKS



EXAMPLE

13831 belongs to the sequence as it is a palindromic prime in which the digits are increasing up to the middle digit 8 and then decreasing.


PROG

(Python)
from sympy import isprime
from itertools import combinations
def agen():
for digits in range(1, 19):
for left in combinations("123456789", (digits+1)//2):
left = "".join(left)
yield int(left + (left[:digits//2])[::1])


CROSSREFS



KEYWORD

nonn,base,easy,fini,full


AUTHOR



EXTENSIONS



STATUS

approved



