A062352 Palindromic primes with strictly decreasing digits up to the middle and then strictly increasing.

2, 3, 5, 7, 11, 101, 313, 727, 757, 919, 929, 31013, 73037, 73237, 74047, 76367, 91019, 93139, 93239, 94049, 94349, 96269, 96469, 97379, 97579, 98389, 98689, 7310137, 7521257, 7540457, 7630367, 7632367, 7654567, 9320239, 9610169

Offset

1,1

Comments

The last term of this finite series is 97654321012345679.

There are 84 terms. - Michael S. Branicky, Aug 04 2022

Links

Michael S. Branicky, Table of n, a(n) for n = 1..84 (full sequence)

Patrick De Geest, World of Palindromic Primes

Example

31013 belongs to the sequence as it is a palindromic prime in which the digits are decreasing up to the middle digit 0 and then increasing.

Prog

(Python)
from sympy import isprime
from itertools import combinations
def bgen():
    for digits in range(1, 20):
        for left in combinations("9876543210", (digits+1)//2):
            left = "".join(left)
            yield int(left + (left[:digits//2])[::-1])
afull = sorted(filter(isprime, bgen()))
print(afull) # Michael S. Branicky, Aug 04 2022

Crossrefs

Cf. A062351.

Sequence in context: A229107 A109574 A084837 * A033938 A069598 A049575

Adjacent sequences: A062349 A062350 A062351 * A062353 A062354 A062355

Keyword

nonn,base,fini,full

Author

Amarnath Murthy, Jun 23 2001

Extensions

Corrected and edited by Patrick De Geest, Jun 07 2003

Status

approved