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

1,1

Links

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

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

Example

1/1332 = 0.000750750750...

Mathematica

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

Prog

(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

Crossrefs

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

Sequence in context: A266963 A180961 A278643 * A159259 A365960 A097228

Adjacent sequences: A069102 A069103 A069104 * A069106 A069107 A069108

Keyword

base,easy,nonn

Author

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

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

Status

approved