A284432 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) and a minimal sum (i.e., the sum of the sequence is A282168(n)).

1, 1, 2, 2, 4, 4, 4, 48, 48, 144

Offset

1,3

Links

Table of n, a(n) for n=1..10.

Example

For n = 7 the a(7) = 4 solutions are:
[1,3,3,2,2,1,1],
[1,2,2,3,3,1,1],
[1,1,3,3,2,2,1], and
[1,1,2,2,3,3,1].

Crossrefs

Cf. A282168.

Sequence in context: A083548 A082849 A211882 * A284435 A156130 A123756

Adjacent sequences: A284429 A284430 A284431 * A284433 A284434 A284435

Keyword

nonn,more

Author

Peter Kagey, Mar 27 2017

Status

approved