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A066024
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Numbers k such that the product of the digits of k minus the sum of the digits of k is prime.
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2
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24, 25, 27, 29, 33, 34, 35, 37, 38, 42, 43, 45, 47, 49, 52, 53, 54, 56, 57, 59, 65, 67, 72, 73, 74, 75, 76, 78, 79, 83, 87, 92, 94, 95, 97, 125, 126, 128, 133, 144, 146, 148, 152, 162, 164, 166, 182, 184, 188, 215, 216, 218, 222, 223, 225, 227, 229, 232, 245, 247
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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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a(1)=24 because 2 + 4 = 6, 2*4 = 8, and 8 - 6 = 2, which is prime. [corrected by Harry J. Smith, Nov 07 2009]
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PROG
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(PARI) ProdD(x)= { local(p=1); while (x>9 && p>0, p*=x%10; x\=10); return(p*x) } SumD(x)= { local(s=0); while (x>9, s+=x%10; x\=10); return(s + x) } { n=0; for (m=1, 10^9, if (isprime(ProdD(m) - SumD(m)), write("b066024.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Nov 07 2009
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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STATUS
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approved
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