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A062352 Palindromic primes with strictly decreasing digits up to the middle and then strictly increasing. 6
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 (list; graph; refs; listen; history; text; internal format)
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
KEYWORD
nonn,base,fini,full
AUTHOR
Amarnath Murthy, Jun 23 2001
EXTENSIONS
Corrected and edited by Patrick De Geest, Jun 07 2003
STATUS
approved

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Last modified June 21 01:33 EDT 2024. Contains 373535 sequences. (Running on oeis4.)