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Numbers in the range of the sum of deficient divisors function.
2

%I #10 Jul 14 2016 00:19:51

%S 1,3,4,6,7,8,10,12,13,14,15,18,19,20,22,24,27,28,30,31,32,34,36,38,40,

%T 42,43,44,46,48,52,54,56,57,60,62,63,64,66,68,70,72,74,75,76,78,80,84,

%U 86,90,92,93,94,96,97,98,102,104,105,106,108,110,112,114,118,120,121,122,123,124,126,127,128,130,132,133,134,135,138,139,140,142,144,148,150,151,152,153,154,156,158

%N Numbers in the range of the sum of deficient divisors function.

%C Possible values for the sum of deficient divisors of the positive integers, written in ascending order.

%t Take[#, 100] &@ Union@ Table[Total@ Select[Divisors@ n, DivisorSigma[1, #] < 2 # &], {n, 10^4}] (* _Michael De Vlieger_, Jul 13 2016 *)

%Y Cf. A005100, A187793, A210510 (complement).

%K nonn

%O 1,2

%A _Timothy L. Tiffin_, Jul 07 2016