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A257275
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Numbers equal to some partial product of the sequence of their digits, repeated over and over again.
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1
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1, 2, 3, 4, 5, 6, 7, 8, 9, 735, 18432, 442368, 3682784876146817236992
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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The sequence is conjectured to be finite (D. Wilson, Reply on the SeqFan list).
There are no additional terms below 10^300. - Max Alekseyev, Apr 29 2015
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LINKS
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EXAMPLE
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735 = 7 * 3 * 5 * 7
18432 = 1 * 8 * 4 * 3 * 2 * 1 * 8 * 4 * 3
442368 = 4 * 4 * 2 * 3 * 6 * 8 * 4 * 4 * 2 * 3
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MATHEMATICA
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Select[Range[450000], MemberQ[FoldList[Times, PadRight[{}, 50, IntegerDigits[#]]], #]&] (* The program will generate the first 12 terms of the sequence. *) (* Harvey P. Dale, Jun 21 2017 *)
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PROG
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(PARI) is(n, d=digits(n), p=1)=for(i=0, n, (n>p*=d[i%#d+1])||return(n==p))
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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