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A084837
Palindromic primes with nonincreasing digits up to the middle and then nondecreasing.
2
2, 3, 5, 7, 11, 101, 313, 727, 757, 919, 929, 31013, 72227, 73037, 73237, 74047, 75557, 76367, 76667, 77377, 77477, 91019, 93139, 93239, 94049, 94349, 96269, 96469, 97379, 97579, 98389, 98689, 3211123, 3222223, 3310133, 3321233, 3331333, 7100017, 7300037, 7310137
OFFSET
1,1
LINKS
Patrick De Geest, World of Palindromic Primes
PROG
(Python)
from sympy import isprime
from itertools import count, islice, combinations_with_replacement as mc
def agen(): # generator of terms
yield from (2, 3, 5, 7, 11)
for d in count(2):
nind = (int("".join(m+m[:-1][::-1])) for m in mc("9876543210", d))
yield from sorted(filter(isprime, nind))
print(list(islice(agen(), 40))) # Michael S. Branicky, Jun 26 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jun 07 2003
EXTENSIONS
a(38) and beyond from Michael S. Branicky, Jun 26 2022
STATUS
approved