A357328 - OEIS

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A357328

Number of permutations p of [n] such that p(i) divides p(j) if i divides j for 1 <= i <= j <= n.

1, 1, 1, 2, 1, 2, 1, 2, 2, 2, 1, 2, 2, 6, 4, 2, 2, 6, 6, 24, 24, 24, 6, 24, 24, 24, 12, 12, 12, 48, 48, 240, 240, 120, 48, 48, 48, 240, 144, 96, 96, 480, 480, 2880, 1440, 1440, 720, 4320, 4320, 4320, 4320, 2880, 2880, 20160, 20160, 10080, 10080, 10080, 2880, 20160, 20160, 161280, 60480, 60480, 60480, 120960

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

COMMENTS

a(n) >= 1.

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..5000

EXAMPLE

For n = 14, the 4 permutations are:

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 12, 11, 14]

[1, 2, 3, 4, 7, 6, 5, 8, 9, 14, 11, 12, 13, 10]