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A339490
Number of longest simple paths in the divisor graph of {1,...,n}.
2
1, 2, 2, 4, 8, 4, 8, 16, 16, 40, 40, 8, 12, 24, 88, 176, 192, 48, 64, 224, 704, 896, 896, 32, 140, 72, 72, 312, 312, 88, 88, 176
OFFSET
1,2
EXAMPLE
The longest paths for n = 13. The ones marked with (*) are also the longest paths for n = 12.
[5, 10, 2, 8, 4, 12, 6, 3, 9, 1, 7], (*)
[5, 10, 2, 8, 4, 12, 6, 3, 9, 1, 11], (*)
[5, 10, 2, 8, 4, 12, 6, 3, 9, 1, 13],
[7, 1, 5, 10, 2, 8, 4, 12, 6, 3, 9], (*)
[7, 1, 9, 3, 6, 12, 4, 8, 2, 10, 5], (*)
[9, 3, 6, 12, 4, 8, 2, 10, 5, 1, 7], (*)
[9, 3, 6, 12, 4, 8, 2, 10, 5, 1, 11], (*)
[9, 3, 6, 12, 4, 8, 2, 10, 5, 1, 13],
[11, 1, 5, 10, 2, 8, 4, 12, 6, 3, 9], (*)
[11, 1, 9, 3, 6, 12, 4, 8, 2, 10, 5], (*)
[13, 1, 5, 10, 2, 8, 4, 12, 6, 3, 9],
[13, 1, 9, 3, 6, 12, 4, 8, 2, 10, 5].
CROSSREFS
Sequence in context: A366714 A359488 A183397 * A281469 A302623 A302415
KEYWORD
nonn,more,hard
AUTHOR
Peter Luschny, Dec 27 2020
EXTENSIONS
a(14)-a(32) from Pontus von Brömssen, Dec 29 2020
STATUS
approved