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A231848
A sequence of rounded numbers meaningful for entering values over several orders of magnitude in computer-human interfaces.
1
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500
OFFSET
1,2
COMMENTS
A slider in a user interface is often hard to represent when the range of numbers is large. This sequence produces a list of numbers that make it possible to select a meaningful value at all orders of magnitude.
FORMULA
n <= 9: n,
n > 9: (((n+8) mod 18)/2 + 1) * 10^(floor((n+8)/18)).
MATHEMATICA
Table[If[n <= 9, n, (Mod[n + 8, 18]/2 + 1)*10^Floor[(n + 8)/18]], {n, 50}] (* T. D. Noe, Nov 27 2013 *)
CROSSREFS
Sequence in context: A117924 A374561 A239616 * A200373 A140335 A004839
KEYWORD
nonn,easy
AUTHOR
Lasse Klein, Nov 14 2013
STATUS
approved