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A262996
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Ten-digit semiprimes with exactly one 1, two 2's, three 3's and four 4's.
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1
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1223444433, 1224343443, 1233444243, 1233444423, 1234424343, 1234442343, 1243344243, 1243442433, 1244332443, 1244343423, 1244344323, 1244442333, 1323442443, 1324244433, 1324344423, 1324443243, 1324443423, 1324444323, 1332244443, 1334244243, 1334244423, 1334424243, 1342443243, 1343242443
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listen;
history;
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internal format)
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OFFSET
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1,1
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COMMENTS
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From total 10!/(2!*3!*4!)=12600 ten-digit numbers with exactly one 1, two 2's, three 3's and four 4's, exactly 732 numbers are semiprimes of the form 3*prime.
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LINKS
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MATHEMATICA
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Select[(FromDigits[#] & /@ Permutations[{1, 2, 2, 3, 3, 3, 4, 4, 4, 4}]), PrimeQ[#/3] &]
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PROG
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(PARI) forprime(p=407814811, 1481443741, d=digits(3*p); if(vecsort(d)==[1, 2, 2, 3, 3, 3, 4, 4, 4, 4], print1(3*p", "))) \\ Charles R Greathouse IV, Sep 24 2015
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CROSSREFS
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KEYWORD
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nonn,base,fini,full
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AUTHOR
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STATUS
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approved
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