A284431 The number of positive integer sequences of length n with no duplicate substrings of length greater than 1, every number different from its neighbors, and a minimal sum (= A282166(n)).

1, 2, 1, 6, 2, 42, 12, 116, 18, 84, 168, 336, 384, 6864, 7872, 67392, 52800, 357120, 115200, 748800, 3093120, 11681280, 26853120, 43130880, 74649600, 2238382080, 3588157440, 51775856640, 63188398080, 653811056640, 480220876800, 4284050964480, 1316818944000, 11061279129600, 76921038028800

Offset

1,2

Links

Table of n, a(n) for n=1..35.

Example

For n = 5, the a(5) = 2 sequences are [1,3,1,2,1] and [1,2,1,3,1], each with a sum of A282166(5) = 8.

Crossrefs

Cf. A282166, A283558, A284432, A284433, A284434.

Sequence in context: A306543 A243484 A181811 * A333078 A352376 A337470

Adjacent sequences: A284428 A284429 A284430 * A284432 A284433 A284434

Keyword

nonn

Author

Peter Kagey, Mar 27 2017

Extensions

Terms a(9) onward from Max Alekseyev, Feb 06 2025

Status

approved