A306272 Sum of distinct distances between n non-attacking rooks over all n X n chessboards.

0, 2, 12, 78, 686, 6056, 59002, 616522, 7009264, 86023126

Offset: 1

Author

Peter Kagey, Feb 01 2019

Keywords

• nonn
• more

Comments

a(n)/n! gives the expected number of distinct distances of n non-attacking rooks on a random n X n chessboard.

n!*A319476(n) <= a(n) <= n!*A320448(n).

Crossrefs

Cf. A319476, A320448.