A162820 Positive numbers n such that 60*n/(60+n) are integers.

12, 15, 20, 30, 40, 60, 84, 90, 120, 140, 165, 180, 240, 300, 340, 390, 540, 660, 840, 1140, 1740, 3540

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Keywords

• nonn
• fini
• full

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819

Cf. A127730. [From Franklin T. Adams-Watters, Aug 07 2009]

Programs

Mathematica

f[a_,b_]:=(a*b)/(a+b); a=60;lst={};Do[If[f[a,n]==IntegerPart[f[a,n]], AppendTo[lst,n]],{n,9!}];lst

Extensions

Keywords fini,full added by R. J. Mathar, Jul 31 2009