A259704 Triangle read by rows: T(n,k) = number of overlaps formed by element 1 in the set of permutations of n elements, where the element n does not occupy the k-th place after 1.

0, 0, 0, 1, 0, 1, 2, 2, 2, 2, 20, 14, 12, 14, 20, 80, 80, 80, 80, 80, 80, 840, 720, 648, 624, 648, 720, 840

Offset

2,7

References

A. Sade, Sur les Chevauchements des Permutations, published by the author, Marseille, 1949.

Links

Table of n, a(n) for n=2..29.

Albert Sade, Sur les Chevauchements des Permutations, published by the author, Marseille, 1949. [Annotated scanned copy]

Example

Triangle begins:
0,
0,0,
1,0,1,
2,2,2,2,
20,14,12,14,20,
80,80,80,80,80,80,
840,720,648,624,648,720,840,
...

Crossrefs

Row sums are A259705.

Sequence in context: A029643 A100687 A067096 * A249779 A167394 A029627

Adjacent sequences: A259701 A259702 A259703 * A259705 A259706 A259707

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Jul 05 2015

Status

approved