OFFSET
0,2
COMMENTS
Gives the number of possible chess games where both sides start without rooks. Rooks are still allowed to appear later in the game through promotion.
Does not include games which end in fewer than n plies.
The total number of such games should be less than the total number of standard chess games, and it appears A285874(n) <= A048987(n) for all n.
Initial terms computed using the Chesspresso engine.
LINKS
Bernhard Seybold, Chesspresso.
CROSSREFS
KEYWORD
nonn,hard,more,fini
AUTHOR
Sean A. Irvine, Apr 28 2017
EXTENSIONS
a(9) from Sean A. Irvine, May 04 2017
STATUS
approved