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Values of n such that the perfect deficiency (A109883) of n is a square.
1

%I #8 Dec 15 2017 17:36:57

%S 1,2,4,5,6,8,14,16,17,24,28,32,37,38,42,44,64,72,92,98,101,110,128,

%T 134,152,170,172,180,186,192,197,206,248,252,256,257,284,374,398,401,

%U 410,428,434,474,480,496,512,577,590,604,616,632,638,677,752,760,864,884

%N Values of n such that the perfect deficiency (A109883) of n is a square.

%t subtract = If[ #1 < #2, Throw[ #1], #1 - #2]&; f[n_] := Catch @ Fold[subtract, n, Divisors @ n]; Select[ Range[905], IntegerQ[ Sqrt[ f[ # ]]] &] (* _Robert G. Wilson v_, Jul 21 2005 *)

%Y Cf. A110278.

%K nonn

%O 1,2

%A _Jason Earls_, Jul 18 2005