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A066521
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Primes p(k) such that the product of digits of p(k) equals the product of digits of k.
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1
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17, 181, 443, 491, 1163, 2131, 2143, 2153, 2621, 4253, 4621, 7691, 11483, 11593, 11813, 23819, 26951, 27179, 32261, 32443, 33811, 35171, 35227, 37643, 41543, 42433, 42443, 44623, 44917, 45971, 51473, 54517, 58193, 61223, 63131, 64591
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OFFSET
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1,1
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COMMENTS
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Numbers with product of digits=0, like prime(80) = 409, are not included. - Harry J. Smith, Feb 20 2010
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LINKS
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EXAMPLE
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181 is the 42nd prime and the product of digits of both is 8.
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MATHEMATICA
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Select[Table[{n, Prime[n]}, {n, 6500}], DigitCount[#[[1]], 10, 0]==0 && Times@@ IntegerDigits[#[[1]]]==Times@@IntegerDigits[#[[2]]]&][[All, 2]] (* Harvey P. Dale, Oct 17 2020 *)
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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) } { n=0; for (m=1, 10^10, p=prime(m); d=ProdD(m); if (ProdD(p) == d && d, write("b066521.txt", n++, " ", p); if (n==1000, return)) ) } \\ Harry J. Smith, Feb 20 2010
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CROSSREFS
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KEYWORD
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base,less,nonn
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AUTHOR
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STATUS
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approved
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