A374086 Number of integer sequences on a circle of length A373728(n) containing all permutations of the set {1, 2, ..., n} as subsequences.

1, 2, 18, 288, 14760

Offset: 1

Author

Chai Wah Wu, Jun 27 2024

Keywords

• nonn
• hard
• more

Comments

a(n) is a multiple of n!.

Examples

			a(1) = 1  as '1' is the only sequence of length A373728(1) = 1.
a(2) = 2  corresponding to the sequences of length A373728(2) = 2 : {'12', '21'}.
a(3) = 18 corresponding to the sequences of length A062714(3) = 4 : {'1213', '1231', '1232', '1312', '1321', '1323', '2123', '2131', '2132', '2312', '2313', '2321', '3121', '3123', '3132', '3212', '3213', '3231'}.
		

Crossrefs

Cf. A062714, A373728, A374085.