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A333607
Numbers k with unique nonzero digit in decimal representation of 1/k.
1
1, 2, 3, 5, 9, 10, 11, 15, 18, 20, 25, 30, 33, 45, 50, 90, 99, 100, 101, 110, 111, 125, 150, 165, 180, 198, 200, 225, 250, 300, 303, 330, 333, 450, 495, 500, 900, 909, 990, 999, 1000, 1001, 1010, 1100, 1110, 1111, 1125, 1250, 1287, 1500, 1515, 1650, 1665, 1800
OFFSET
1,2
COMMENTS
This sequence has similarities with A125289; here we consider the decimal representation of 1/n, there that of n.
This sequence contains A333402.
If m belongs to the sequence, then 10*m also belongs to the sequence.
EXAMPLE
The first terms, alongside their inverse, are:
n a(n) 1/a(n)
-- ---- -----------
1 1 1
2 2 0.5
3 3 0.333333...
4 5 0.2
5 9 0.111111...
6 10 0.1
7 11 0.090909...
8 15 0.066666...
9 18 0.055555...
10 20 0.05
11 25 0.04
12 30 0.033333...
13 33 0.030303...
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A127149 A047606 A226826 * A047370 A226820 A072192
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 28 2020
STATUS
approved