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A126076
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Numbers such that the sum of the factorials of the digits of the cube is a square.
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2
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1, 7, 10, 36, 54, 62, 600, 658, 692, 823, 888, 907, 1200, 1389, 1898, 2100, 2171, 2824, 3177, 3344, 3711, 3938, 4680, 5029, 5771, 6737, 6787, 6813, 7517, 9600, 9955, 10436, 11356, 12169, 12867, 12967, 13105, 13588, 13879, 14707, 14867, 15400, 15513
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OFFSET
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1,2
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LINKS
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EXAMPLE
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a(4)=36, 36^3 = 46656, (4! + 6! + 6! + 5! + 6!) = 2304 = 48^2.
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MAPLE
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a:=proc(n) local nn: nn:=convert(n^3, base, 10): if type(sqrt(add(nn[j]!, j=1..nops(nn))), integer)=true then n else fi end: seq(a(n), n=1..20000); # Emeric Deutsch, Mar 06 2007
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MATHEMATICA
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Select[Range[20000], IntegerQ[Sqrt[Total[IntegerDigits[#^3]!]]]&] (* Vincenzo Librandi, Mar 29 2014 *)
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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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EXTENSIONS
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STATUS
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approved
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