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A180561
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Primes that cannot become a different prime under any mapping of some single decimal digit <=> with some other single decimal digit.
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46
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11, 11779, 22669, 23333, 33533, 55333, 74279, 77999, 78857, 80603, 84871, 88177, 88747, 97039, 103091, 112181, 119701, 125813, 128147, 131143, 133499, 141587, 158771, 159979, 164341, 166063, 173933, 175781, 219613, 220279, 222601, 227387, 229727, 231317, 238829
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, s[[1]]] || MemberQ[id, s[[2]]]) && PrimeQ[ FromDigits[id /. {s[[1]] -> s[[2]], s[[2]] -> s[[1]] }] ]]; t = Union@ Flatten@ Table[s = {j, k}; Select[ Prime@ Range@ 25000, fQ], {j, 0, 8}, {k, j + 1, 9}] ]]; Complement[ Prime@ Range@ 25000, t]
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PROG
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(Python)
from sympy import isprime
def m(s):
return [s.translate({ord(c):ord(d), ord(d):ord(c)}) for c in set(s) for d in "0123456789" if d != c]
def ok(n):
return isprime(n) and not any(isprime(int(t)) for t in m(str(n)))
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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