OFFSET
0,3
REFERENCES
A. Laradji and A. Umar, On the number of subpermutations with fixed orbit size, Ars Combinatoria, 109 (2013), 447-460.
FORMULA
EXAMPLE
T(3, 2) = 26 because there are 26 subpermutations on {1,2,3}, each of whose orbit is of size at most 2, namely:
Empty map, 1-->1, 1-->2, 1-->3, 2-->1, 2-->2, 2-->3, 3-->1, 3-->2, 3-->3, (1,2) --> (1,2), (1,3) --> (1,3), (2,3) --> (2,3), (1,2) --> (2,1), (1,3) --> (3,1), (2,3) --> (3,2), (1,2) --> (1,3), (1,3) --> (1,2), (2,3) --> (2,1), (1,2) --> (3,2), (1,3) --> (2,3), (2,3) --> (1,3), (1,2,3) --> (1,3,2), (1,2,3) --> (3,2,1), (1,2,3) --> (2,1,3), (1,2,3) --> (1,2,3).
Triangle starts:
1;
1, 2;
1, 4, 7;
1, 8, 26, 34;
1, 16, 115, 179, 209;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Samira Stitou, Sep 21 2015
EXTENSIONS
More terms from Alois P. Heinz, Oct 07 2015
STATUS
approved