A070023 1/n has period 1 in base 10 (including terminating decimals).

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 30, 32, 36, 40, 45, 48, 50, 60, 64, 72, 75, 80, 90, 96, 100, 120, 125, 128, 144, 150, 160, 180, 192, 200, 225, 240, 250, 256, 288, 300, 320, 360, 375, 384, 400, 450, 480, 500, 512, 576, 600, 625, 640, 720, 750

Offset: 1

Author

Henry Bottomley, Apr 12 2002

Keywords

• base
• nonn

Examples

			12 is in the sequence since 1/12 = 0.08333333333...
11 is not since 1/11 = 0.0909090909...
10 is in, since 1/10 = 0.1000000... = 0.099999999...
		

Crossrefs

Cf. A003592, A069105, A070021, A070022.

Programs

Mathematica

Select[Range[750], Length[RealDigits[1/#][[1, -1]]] <= 1 &] (* Amiram Eldar, Jun 12 2022 *)

Formula

a(n) = A070022(n)/11. Numbers of the form a*b*c where a is in {1, 3, 9}, b is a power of 2 and c is a power of 5.