A144672 Numbers x,y,z such that UnitarySigma(x) = UnitarySigma(y) = UnitarySigma(z) = 3*(x*y*z)^(1/2)/(- x^(1/2) + 8*y^(1/2) - 5*z^(1/2)), z<=y<=x; sequence gives x.

2, 20, 24, 360, 816, 1056, 12240, 15840, 29120, 181632, 337977, 2724480, 93358848, 1400382720

Offset: 1

Author

Yasutoshi Kohmoto, Feb 02 2009

Keywords

• nonn
• more

Comments

a(11) is the smallest term for x!=y, y!=z, x!=z.

If x=y=z then we get multiply unitary perfect numbers such that UnitarySigma(x)=3x/2.

Examples

			Factorization of a(11) : 17*3^2*47^2.
		

Crossrefs

Cf. A034448, A144673, A144674 (these entries all differ at a(11)).