A258110 Number of Mirror Chess games that end in checkmate after exactly n moves.

0, 0, 0, 0, 3, 212, 10592, 449977, 17727425, 680781219, 26046238416, 1001222256515, 38764377926857, 1511202832516487

Offset

0,5

Links

Table of n, a(n) for n=0..13.

J. Loy, A Mirror Chess Problem

Example

a(4) = 3 because of these checkmates:
1. c4 c5 2. Qa4 Qa5 3. Qc6 Qc3 4. Qxc8#
1. d4 d5 2. Qd3 Qd6 3. Qh3 Qh6 4. Qxc8#
1. d4 d5 2. Qd3 Qd6 3. Qf5 Qf4 4. Qxc8#

Crossrefs

Cf. A079485, A136257.

Sequence in context: A349073 A063407 A303214 * A072196 A038785 A297920

Adjacent sequences: A258107 A258108 A258109 * A258111 A258112 A258113

Keyword

nonn,hard,more,fini

Author

Jeremy Gardiner, May 20 2015

Extensions

a(5)-a(13) from François Labelle, May 25 2015

Status

approved