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A162825
Positive numbers k such that 60*k/(60-k) are integers.
5
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 *)
KEYWORD
nonn,easy,fini,full
AUTHOR
EXTENSIONS
Keyword fini added by R. J. Mathar, Jul 31 2009
STATUS
approved