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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A205554 Least positive integer k such that n divides k^(k-1)-j^(j-1) for some j in [1,k-1]. 1
2, 3, 4, 3, 4, 5, 3, 3, 4, 7, 4, 5, 5, 5, 7, 5, 5, 7, 7, 7, 4, 5, 6, 5, 6, 5, 7, 5, 12, 8, 4, 6, 5, 7, 11, 7, 9, 7, 5, 7, 8, 13, 7, 5, 7, 6, 12, 5, 8, 8, 5, 5, 7, 12, 4, 5, 7, 12, 12, 11, 12, 4, 4, 8, 7, 8, 7, 7, 7, 11, 7, 7, 9, 9, 8, 7, 5, 5, 8, 9, 9, 8, 10, 13, 7, 7, 14, 5, 5, 13, 16, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For a guide to related sequences, see A204892.

LINKS

Table of n, a(n) for n=1..92.

EXAMPLE

1 divides 2^(2-1)-1^(1-1) -> k=2, j=1

2 divides 3^(3-1)-1^(1-1) -> k=3, j=1

3 divides 4^(4-1)-1^(1-1) -> k=4, j=1

4 divides 3^(3-1)-1^(1-1) -> k=3, j=1

5 divides 4^(4-1)-3^(3-1) -> k=4, j=3

MATHEMATICA

s = Table[n^(n-1), {n, 1, 120}];

lk = Table[NestWhile[# + 1 &, 1,

   Min[Table[Mod[s[[#]] - s[[j]], z], {j, 1, # - 1}]] =!= 0 &], {z, 1, Length[s]}]

Table[NestWhile[# + 1 &, 1,

  Mod[s[[lk[[j]]]] - s[[#]], j] =!= 0 &],

{j, 1, Length[lk]}]

(* Peter J. C. Moses, Jan 27 2012 *)

CROSSREFS

Cf. A204892, A205546, A000169.

Sequence in context: A030563 A081399 A221108 * A214613 A325933 A114524

Adjacent sequences:  A205551 A205552 A205553 * A205555 A205556 A205557

KEYWORD

nonn

AUTHOR

Clark Kimberling, Feb 01 2012

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 September 20 01:58 EDT 2019. Contains 327207 sequences. (Running on oeis4.)