A084836 Palindromic primes with nondecreasing digits up to the middle and then nonincreasing.

2, 3, 5, 7, 11, 131, 151, 181, 191, 353, 373, 383, 787, 797, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14741, 15551, 16661, 17971, 19991, 33533, 34543, 34843, 35753, 77977, 78887, 79997, 1114111, 1117111, 1123211, 1126211, 1129211, 1134311

Offset

1,1

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

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():
    yield from (2, 3, 5, 7, 11)
    for d in count(2):
        ndni = (int("".join(m+m[:-1][::-1])) for m in mc("123456789", d))
        yield from filter(isprime, ndni)
print(list(islice(agen(), 40))) # Michael S. Branicky, Jun 26 2022

Crossrefs

Cf. A084837, A062351, A062352.

Sequence in context: A069598 A049575 A070028 * A062351 A185267 A088249

Adjacent sequences: A084833 A084834 A084835 * A084837 A084838 A084839

Keyword

nonn,base

Author

Patrick De Geest, Jun 07 2003

Extensions

a(39) and beyond from Michael S. Branicky, Jun 26 2022

Status

approved