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A205791 Least positive integer k such that n divides k^5-j^5 for some j in [1,k-1]. 1
2, 3, 4, 4, 6, 7, 8, 4, 6, 11, 3, 8, 14, 15, 16, 4, 18, 9, 20, 12, 22, 3, 24, 8, 6, 27, 6, 16, 30, 31, 2, 4, 4, 35, 36, 12, 38, 39, 40, 12, 7, 43, 44, 5, 18, 47, 48, 8, 14, 11, 52, 28, 54, 9, 7, 16, 58, 59, 60, 32, 7, 4, 24, 6, 66, 8, 68, 36, 70, 71, 4, 12, 74, 75, 16, 40 (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..76.

EXAMPLE

1 divides 2^5-1^5 -> k=2, j=1

2 divides 3^5-1^5 -> k=3, j=1

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

4 divides 4^5-2^5 -> k=4, j=2

5 divides 6^5-1^5 -> k=6, j=1

6 divides 7^5-1^5 -> k=7, j=1

MATHEMATICA

s = Table[n^4, {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.

Sequence in context: A089266 A178993 A193768 * A039696 A076332 A245092

Adjacent sequences:  A205788 A205789 A205790 * A205792 A205793 A205794

KEYWORD

nonn

AUTHOR

Clark Kimberling, Feb 01 2012

STATUS

approved

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Last modified January 26 23:05 EST 2020. Contains 331289 sequences. (Running on oeis4.)