A108414 - OEIS

A108414

Number of integer k:s for which max{x^(k-x) | x integer, 0<x<k} = n^(k-n).

1, 2, 3, 4, 3, 4, 4, 4, 4, 5, 4, 5, 4, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6

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OFFSET

1,2

COMMENTS

Consider the following triangle:

...................1

................1..-..2

............1......4..-..3

.........1......8..-..9.....4

......1....16.....27..-.16....5

....1...32.....81.--.64....25...6

.1...64...243..--256...125...36..7

1.128..729...1024---625...216..49.8

.............----..................

The first row is 1^1, the 2nd row is 1^2, 2^1, the 3rd row is 1^3, 2^2, 3^1 ... the m-th row is 1^m, ..., m^1. The maximum element in each row is marked. The marked elements lie in downward-sloping chains. This sequence gives the lengths of those chains.

LINKS

Table of n, a(n) for n=1..25.

CROSSREFS

Sequence in context: A030398 A030384 A067349 * A253250 A097477 A059572

Adjacent sequences: A108411 A108412 A108413 * A108415 A108416 A108417

KEYWORD

nonn

AUTHOR

Jonas Wallgren, Jul 04 2005

STATUS

approved