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A069105
1/n has period 3 in base 10.
6
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
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
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