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%I #10 Jul 06 2020 19:05:44
%S 3,102,122,202,1102,15031,244134,244233,434412,495918,1267396,1300035,
%T 1324340,1635150,3442657,3878374,5064314,6175125,6181308,10320734,
%U 10560355,10586434,10730603,10804230,11544642,16224135,17523855
%N Numbers n such that concatenating n and the sum of factorials of the digits of n produces a square.
%e 495918 is in the sequence because 4!+9!+5!+9!+1!+8! = 766225 and
%e 495918766225 = 704215^2.
%t sfdsQ[n_]:=Module[{f=Total[IntegerDigits[n]!]},IntegerQ[ Sqrt[ n*10^IntegerLength[ f]+ f]]]; Select[Range[176*10^5],sfdsQ] (* _Harvey P. Dale_, Jul 06 2020 *)
%Y Cf. A061602, A109016.
%K base,nonn
%O 1,1
%A _Jason Earls_, Jun 16 2005
%E Extended by _Don Reble_, Nov 21 2006
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