A139718 A number n is included if |k - n/k| divides n for at least one divisor k of n.

2, 6, 8, 12, 18, 20, 24, 30, 32, 36, 42, 48, 50, 54, 56, 60, 72, 80, 90, 96, 98, 108, 110, 120, 128, 132, 140, 144, 150, 156, 162, 168, 180, 182, 192, 200, 210, 216, 224, 240, 242, 252, 270, 272, 288, 294, 300, 306, 320, 324, 336, 338, 342, 350, 360, 378, 380

Offset: 1

Author

Leroy Quet, May 01 2008

Keywords

• nonn

Comments

All terms are even. All positive integers of the form n(n+1) are included.

Examples

			36 is included because 3 is a divisor of 36 and |3 - 36/3| = 9 divides 36.
		

Links

• Alexis Olson, Table of n, a(n) for n = 1..526

Crossrefs

Cf. A139719.

Programs

Mathematica

For[n = 1; s = {}, n <= 1000, n++,
  For[i = 1, i <= Length[Divisors[n]], i++, k = Divisors[n][[i]];
    If[Abs[k-n/k]>0&&Mod[n, Abs[k-n/k]]==0,s=Union[s,{n}];Break[]]]];s (* Alexis Olson (AlexisOlson(AT)gmail.com), Nov 14 2008 *)
odkQ[n_]:=Module[{d=Divisors[n],nz},nz=#-n/#&/@d; MemberQ[Divisible[ n,Abs[Select[nz,#!=0&]]],True]]; Select[Range[400],odkQ] (* Harvey P. Dale, May 06 2012 *)

Extensions

More terms from Alexis Olson (AlexisOlson(AT)gmail.com), Nov 14 2008