A069105 1/n has period 3 in base 10.

27, 37, 54, 74, 108, 111, 135, 148, 185, 216, 222, 270, 296, 333, 370, 432, 444, 540, 555, 592, 666, 675, 740, 864, 888, 925, 999, 1080, 1110, 1184, 1332, 1350, 1480, 1665, 1728, 1776, 1850, 1998, 2160, 2220, 2368, 2664, 2700, 2775, 2960, 3330, 3375, 3456, 3552, 3700, 3996, 4320, 4440, 4625, 4736, 4995

Offset: 1

Author

Joshua Horowitz (mccartneyman(AT)yahoo.com), Apr 07 2002

Keywords

• base
• easy
• nonn

Examples

			1/1332 = 0.000750750750...
		

Links

• Ray Chandler, Table of n, a(n) for n = 1..348

Crossrefs

Cf. A018766, A003592, A070021, A070022, A070023.

Programs

Mathematica

Select[ Range[7500], Length[ RealDigits[1/# ] [[1, -1]]] == 3 &]

PARI

is(n,S=[27,37,111,333,999])=setsearch(S,n\5^valuation(n,5)>>valuation(n,2)) \\ M. F. Hasler, Apr 25 2017

Formula

Numbers of the form a*b*c where a is in {27, 37, 111, 333, 999}, b is a power of 2 and c is a power of 5. - Henry Bottomley, Apr 12 2002

Equivalently: A132740(n) divides 999 but does not divide 9. - M. F. Hasler, Apr 25 2017

Extensions

Extended by Robert G. Wilson v, Apr 07 2002

Terms added and program corrected to agree with description by Ray Chandler, Apr 17 2017