OFFSET
0,3
EXAMPLE
In case of n = 2.
| permutation
--+-------------
1 | [1, 1, 2, 2]
2 | [1, 2, 1, 2]
3 | [2, 1, 1, 2]
4 | [2, 1, 2, 1]
5 | [2, 2, 1, 1]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Nov 30 2018
EXTENSIONS
a(9) from Alois P. Heinz, Nov 30 2018
STATUS
approved