A162825 Positive numbers k such that 60*k/(60-k) are integers.

10, 12, 15, 20, 24, 30, 35, 36, 40, 42, 44, 45, 48, 50, 51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 72, 75, 76, 78, 80, 84, 85, 90, 96, 100, 105, 108, 110, 120, 132, 135, 140, 150, 160, 180, 204, 210, 240, 260, 285, 300, 360, 420

Offset

1,1

Comments

The number k=60 is explicitly included. The last entry in the sequence is a(68) = 3660.

Row 60 of A191973.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..68 (full sequence)

Maple

for n from 1 to 3660 do if(n=60 or type(60*n/(60-n), integer))then printf("%d, ", n): fi: od: # Nathaniel Johnston, Jun 22 2011

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
Select[Range[500], If[#==60, True, IntegerQ[(60#)/(60-#)]]&] (* Harvey P. Dale, Sep 26 2023 *)

Crossrefs

Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819, A162820, A162821, A162822, A162823, A162824, A191973.

Sequence in context: A054518 A072198 A057485 * A107836 A096128 A334939

Adjacent sequences: A162822 A162823 A162824 * A162826 A162827 A162828

Keyword

nonn,easy,fini,full

Author

Vladimir Joseph Stephan Orlovsky, Jul 13 2009

Extensions

Keyword fini added by R. J. Mathar, Jul 31 2009

Status

approved