A162826 Positive numbers n such that 2*60*n/(60+n) are integers.

12, 15, 20, 30, 36, 40, 60, 84, 90, 100, 120, 140, 165, 180, 228, 240, 300, 340, 390, 420, 540, 660, 740, 840, 1140, 1380, 1740, 2340, 3540, 7140

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Mathematica

f[a_, b_]:=(a*b)/(a+b)*2; a=60; lst={}; Do[If[f[a, n]==IntegerPart[f[a, n]], AppendTo[lst, n]], {n, 9!}]; lst
Select[Range[8000], IntegerQ[(120#)/(60+#)]&] (* Harvey P. Dale, Mar 19 2019 *)

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819, A162820, A162821, A162822, A162823, A162824, A162825

Sequence in context: A156683 A050696 A144266 * A162820 A267195 A353702

Adjacent sequences: A162823 A162824 A162825 * A162827 A162828 A162829

Keyword

nonn,fini,full

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Extensions

Sign in definition flipped by R. J. Mathar, Jul 31 2009

Status

approved