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A084836
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Palindromic primes with nondecreasing digits up to the middle and then nonincreasing.
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3
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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
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OFFSET
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1,1
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LINKS
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PROG
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(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)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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