A162817 Positive numbers n such that 40*n/(40+n) are integers.

10, 24, 40, 60, 120, 160, 280, 360, 760, 1560

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Mathematica

f[a_, b_]:=(a*b)/(a+b); a=40; lst={}; Do[If[f[a, n]==IntegerPart[f[a, n]], AppendTo[lst, n]], {n, 9!}]; lst
Select[Range[1600], IntegerQ[(40#)/(40+#)]&] (* Harvey P. Dale, Oct 11 2011 *)

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694

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

Sequence in context: A063925 A101156 A267431 * A103573 A067728 A352283

Adjacent sequences: A162814 A162815 A162816 * A162818 A162819 A162820

Keyword

nonn,fini,full

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Extensions

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

Status

approved