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Concatenation of Prime Factors is Pandigital (Posted on 2020-10-15) Difficulty: 3 of 5
Please provide the smallest positive base 10 integer, and list its prime factors such that the concatenation of its prime factors includes all 10 decimal digits exactly once.

No Solution Yet Submitted by Larry    
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Solution computer solution -- spoiler | Comment 1 of 2
for n=10000000:99999999
    s=erase(join(string(factor(n)))," ");
    if strlength(s)==10
        ct=zeros(1,10);
        for i=1:10
            p=double(substr(s,i))+1;
            ct(p)=ct(p)+1;
            if ct(p)>1
                break
            end
        end
        if ct(p)==1
            disp(n)
            factor(n)
          disp(s)
        end
    end
end

shows (edited a bit)

    15,618,090
    =
           2 * 3 * 5 * 487 * 1069

If there are any 7-digit numbers with this property we missed them as we started with 8-digit numbers.

Well, I went back and did the 7-digit numbers, by starting with

for n=1000000:9999999

No solutions were found.


  Posted by Charlie on 2020-10-15 10:39:46
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