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A080603
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Primes such that deleting some digit yields a prime.
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38
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13, 17, 23, 29, 31, 37, 43, 47, 53, 59, 67, 71, 73, 79, 83, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 229, 233, 239, 241, 263, 269, 271, 283, 293, 307, 311, 313, 317, 331, 337, 347, 353, 359, 367
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OFFSET
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1,1
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COMMENTS
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Leading zeros are allowed in the number that appears after the digit is deleted, as in A080608. - Michael S. Branicky, Jan 28 2023
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LINKS
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MATHEMATICA
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Q@n_:=AnyTrue[FromDigits@Delete[IntegerDigits@n, #]&/@Range@IntegerLength@n, PrimeQ]; Select[Prime@Range@500, Q@# &] (* Hans Rudolf Widmer, Jun 09 2024 *)
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PROG
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(Python)
from sympy import isprime
def ok(n):
if n < 10 or not isprime(n): return False
s = str(n)
si = (s[:i]+s[i+1:] for i in range(len(s)))
return any(isprime(int(t)) for t in si)
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CROSSREFS
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KEYWORD
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nonn,easy,base
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AUTHOR
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STATUS
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approved
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