login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A284750 a(n) = least k > 0 such that k * n in factorial base representation contains only 0's and 1's. 2
1, 1, 1, 2, 5, 1, 1, 1, 1, 3, 3, 2, 2, 9, 2, 2, 9, 7, 8, 6, 6, 33, 256, 1, 1, 1, 1, 26, 5, 1, 1, 1, 1, 149, 24, 4, 159, 4, 130, 3, 3, 3, 3, 118, 16, 128, 16, 3, 3, 3, 3, 14, 16, 16, 840, 13, 89, 15, 88, 2, 2, 12, 2, 2, 78, 11, 13, 76, 597, 12, 71, 2, 2, 555, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n) = 1 iff n belongs to A059590.

a(a(n)) <= n for any n > 0.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..2000

Wikipedia, Factorial number system

Index entries for sequences related to factorial base representation

FORMULA

a(n) = A286820(n) / n.

EXAMPLE

The first terms, alongside n*a(n) in decimal and factorial base, are:

n     a(n)  n*a(n)  n*a(n) in factorial base

--    ----  ------  ------------------------

1     1     1       1

2     1     2       1,0

3     1     3       1,1

4     2     8       1,1,0

5     5     25      1,0,0,1

6     1     6       1,0,0

7     1     7       1,0,1

8     1     8       1,1,0

9     1     9       1,1,1

10    3     30      1,1,0,0

11    3     33      1,1,1,1

12    2     24      1,0,0,0

13    2     26      1,0,1,0

14    9     126     1,0,1,0,0

15    2     30      1,1,0,0

16    2     32      1,1,1,0

17    9     153     1,1,1,1,1

18    7     126     1,0,1,0,0

19    8     152     1,1,1,1,0

20    6     120     1,0,0,0,0

PROG

(PARI) isA059590(n) = my (r=2); while (n, if (n%r > 1, return (0), n\=r; r++)); return (1)

a(n) = for (k=1, oo, if (isA059590(k*n), return (k)))

CROSSREFS

Cf. A059590, A286820.

Sequence in context: A078506 A323909 A124779 * A092134 A181779 A024548

Adjacent sequences:  A284747 A284748 A284749 * A284751 A284752 A284753

KEYWORD

nonn,base

AUTHOR

Rémy Sigrist, Jun 25 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 06:36 EDT 2019. Contains 322294 sequences. (Running on oeis4.)