OFFSET
0,6
REFERENCES
A. Laradji and A. Umar, On the number of subpermutations with fixed orbit size, Ars Combinatoria, 109 (2013), 447-460.
EXAMPLE
T(n,1) = 0 because there is no (partial) derangement with an orbit of size 1.
T(3,2) = 9 because there are 9 subpermutations on {1,2,3}, whose orbits are each of size at most 2 with at least one orbit of size exactly 2, and without fixed points, namely: (1 2 --> 2 1), (1 3 --> 3 1), (2 3 --> 3 2), (1-->2), (1-->3), (2-->1), (2-->3), (3-->1), (3-->2).
Triangle starts:
1;
1, 0;
1, 0, 3;
1, 0, 9, 8;
1, 0, 45, 32, 30;
1, 0, 165, 320, 150, 144;
1, 0, 855, 2240, 1800, 864, 840;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Samira Stitou, Sep 21 2015
EXTENSIONS
More terms from Alois P. Heinz, Nov 04 2015
STATUS
approved