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A001104
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Numbers n such that n / product of digits of n is a square.
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0
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1, 2, 3, 4, 5, 6, 7, 8, 9, 135, 144, 384, 1575, 1715, 6144, 6912, 11664, 14112, 16224, 18816, 23328, 26136, 31212, 41616, 82944, 83232, 93312, 131424, 131712, 186624, 248832, 371112, 1168128, 2214144, 2239488, 2333772, 3321216, 3881472, 6642432
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OFFSET
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1,2
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LINKS
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MATHEMATICA
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Select[Range[665*10^4], IntegerQ[Sqrt[#/Times@@IntegerDigits[#]]]&]// Quiet (* Harvey P. Dale, May 09 2019 *)
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PROG
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(PARI) isok(n) = {digs = digits(n); q = prod(i=1, #digs, digs[i]); (q != 0) && (n % q == 0) && issquare(n/q); } \\ Michel Marcus, Sep 04 2013
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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