cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-1 of 1 results.

A126685 In chess, the number of checkmate dual-free proof games in n plies.

Original entry on oeis.org

0, 0, 0, 0, 0, 3, 51, 1106, 3813, 47300, 216420, 2057581, 10276981, 74358924
Offset: 0

Views

Author

François Labelle, Feb 13 2007

Keywords

Comments

Among all the proof game problems counted in A090051, this is the number of problems ending in checkmate.

Examples

			a(5)=3 because there are three checkmate proof games in 5 plies:
1. e4 e5 2. Qh5 Ke7 3. Qxe5#
1. e3 e5 2. Qh5 Ke7 3. Qxe5#
1. e4 f5 2. exf5 g5 3. Qh5#

Links

Crossrefs

Cf. A090051, A102784.

Extensions

a(12)-a(13) from François Labelle, Dec 05 2017
Showing 1-1 of 1 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.