A212271 Number of ways to place k non-attacking ferses on an n x n cylindrical chessboard, summed over all k >= 0.

2, 9, 80, 1600, 79033, 8156736, 2055960192, 1108756350625, 1411080429618656, 3943472747846953216, 25425527581172360096017, 365481944233773616212640000, 11980566143208960475692367828480, 882106482533191605447029340350009049, 147314997388032765439791110273770608260928

Offset: 1

Author

Vaclav Kotesovec, May 12 2012

Keywords

• nonn
• hard

Comments

Fers is a leaper [1,1].

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..18
• V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p.443

Crossrefs

Cf. A067965, A067960, A182407, A212269, A212270.

Formula

Limit n ->infinity (a(n))^(1/n^2) is the hard square entropy constant A085850.