A284436 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1, no self-adjacent terms, and a minimal product (= A282170(n)).

1, 2, 6, 2, 18, 12, 24, 24, 792, 240, 1440, 720, 7488, 10080, 16992, 40320, 1013760, 725760, 979200, 3628800, 17902080, 79833600, 89510400, 479001600, 1988582400, 11446272000, 11931494400, 108138240000, 312309043200, 1539772416000, 2186163302400, 19872992563200

Offset

1,2

Links

Table of n, a(n) for n=1..32.

Example

For n = 4 the a(4) = 2 solutions are [1,3,2,1] and [1,2,3,1].

Crossrefs

Cf. A282170, A283557, A284433, A284434, A284435.

Sequence in context: A372620 A236697 A235797 * A284433 A322312 A174857

Adjacent sequences: A284433 A284434 A284435 * A284437 A284438 A284439

Keyword

nonn

Author

Peter Kagey, Mar 27 2017

Extensions

Name edited and terms a(9) onward added by Max Alekseyev, Feb 06 2025

Status

approved