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%I #17 Jan 27 2019 21:07:48
%S 1,39,100,200,305,590,652,700,1207,1270,1900,2302,2491,4666,6697,9282,
%T 10188,10480,11853,12421,13630,13866,14043,14208,14963,15739,15740,
%U 18300,18543,18951,20064,21185,21737,23233,24396,24945,25131,25657
%N Numbers such that the sum of the factorials of the digits of the fourth power is a square.
%H Vincenzo Librandi, <a href="/A126077/b126077.txt">Table of n, a(n) for n = 1..700</a>
%e a(2)=39, 39^4 = 2313441, (2! + 3! + 1! + 3! + 4! + 4! + 1!) = 64 = 8^2.
%p a:=proc(n) local nn: nn:=convert(n^4,base,10): if type(sqrt(add(nn[j]!,j=1..nops(nn))),integer)=true then n else fi end: seq(a(n),n=1..32000); # _Emeric Deutsch_, Mar 06 2007
%t Select[Range[26000],IntegerQ[Sqrt[Total[IntegerDigits[#^4]!]]]&] (* _Harvey P. Dale_, Feb 22 2011 *)
%K nonn,base
%O 1,2
%A _Yalcin Aktar_, Mar 02 2007
%E More terms from _Emeric Deutsch_, Mar 06 2007
%E Name changed by _Franklin T. Adams-Watters_, Mar 29 2014
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