

A006494


Number of possible chess games at the end of the nth ply plus number of games that terminate (i.e., mate) in fewer than n plies.


6



1, 20, 400, 8902, 197281, 4865617, 119060679, 3195913043, 84999425906, 2439540533153, 69353270203366, 2097660204806910, 62855340727822758, 1981075507583376209
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

This sequence is A048987 plus the cumulative sum of A079485.  Richard Bean (rwb(AT)eskimo.com), Jun 18 2003


REFERENCES

James Gleick, Faster, Vintage Books, NY, 2000 (see pp. 259261).


LINKS

Table of n, a(n) for n=0..13.
Eric Weisstein's World of Mathematics, Chess
Index entries for sequences related to number of chess games


CROSSREFS

Cf. A048987, A079485.
Sequence in context: A285874 A007577 A048987 * A007545 A055476 A223180
Adjacent sequences: A006491 A006492 A006493 * A006495 A006496 A006497


KEYWORD

nonn,hard,nice,fini


AUTHOR

Ken Thompson (ken(AT)google.com)


EXTENSIONS

a(8)a(10) from François Labelle, Jan 22 2004
a(11) from François Labelle, Jul 25 2004, who thanks Joost de Heer for providing computer time
a(12) from François Labelle, Mar 04 2012
a(13) from François Labelle, Aug 15 2017


STATUS

approved



