login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A285873 Number of possible chess games at the end of the n-th ply starting without queens. 7
1, 21, 441, 9872, 220447, 5247292, 124278971, 3113440755, 77520962327, 2024021927610 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Gives the number of possible chess games where both sides start without queens.  Queens 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 A285873(n) <= A048987(n) for n >= 7.

Initial terms computed using the Chesspresso engine.

LINKS

Table of n, a(n) for n=0..9.

Chesspresso<sup>TM</sup>.

EXAMPLE

a(1) = 21 because there are 20 usual opening moves plus the additional move of moving the king into the vacant square where the queen would usually be.

CROSSREFS

Cf. A048987 (standard), A285874 (no rooks), A285875 (no knights), A285876 (no bishops), A285877 (no pawns), A285878 (pawns and king).

Sequence in context: A167255 A171295 A009965 * A189433 A041842 A215152

Adjacent sequences:  A285870 A285871 A285872 * A285874 A285875 A285876

KEYWORD

nonn,hard,more,fini

AUTHOR

Sean A. Irvine, Apr 28 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 21 02:33 EDT 2018. Contains 316405 sequences. (Running on oeis4.)