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A364484
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Numbers whose prime factorization (prime factors and exponents) contains the digits 1 and 2 at least once, but no other digits.
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0
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2, 22, 44, 121, 211, 242, 422, 484, 844, 2048, 2111, 2221, 2321, 4096, 4222, 4442, 4642, 8444, 8884, 9284, 12211, 21121, 21211, 21221, 22111, 22528, 23221, 24422, 24431, 25531, 42242, 42422, 42442, 44222, 44521, 45056, 46442, 48844, 48862, 51062, 84484, 84844, 84884, 88444, 89042, 92884, 97724
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OFFSET
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1,1
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LINKS
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EXAMPLE
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9284 is a term because 9284 = 2^2 * 11^1 * 211^1.
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PROG
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(PARI) for(n=1, 1e5, v=[]; s=Set(v); f=factor(n); k=#f[, 1]; for(i=1, k, s1=Set(digits(f[i, 1])); s=setunion(s, s1)); for(i=1, k, s2=Set(digits(f[i, 2])); s=setunion(s, s2)); if(s==[1, 2], print1(n, ", ")))
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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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STATUS
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approved
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