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A126078
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Numbers such that the sum of the factorials of the digits of the fifth power is a square.
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2
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1, 396, 849, 1000, 2807, 4274, 4565, 4971, 5000, 6030, 6487, 6942, 7281, 8210, 11163, 11847, 11895, 15015, 17682, 19043, 19584, 19586, 20500, 20577, 20957, 21315, 23000, 23188, 23397, 25747, 27121, 27720, 29241, 29399, 32160, 34233, 35234
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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(2) = 396, 396^5 = 9738138110976, 9! + 7! + 3! + 8! + 1! + 3! + 8! + 1! + 1! + 0! + 9! + 7! + 6! = 817216 = 904^2.
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MAPLE
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a:=proc(n) local nn: nn:=convert(n^5, base, 10): if type(sqrt(add(nn[j]!, j=1..nops(nn))), integer)=true then n else fi end: seq(a(n), n=1..45000); # Emeric Deutsch, Mar 06 2007
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MATHEMATICA
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Select[Range[50000], IntegerQ[Sqrt[Total[IntegerDigits[#^5]!]]]&] (* 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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