Search: id:A019319 Results 1-1 of 1 results found. %I A019319 %S A019319 1,20,400,5362,71852,815677,9260610,94305342,958605819 %N A019319 Number of possible chess diagrams after n plies. %C A019319 Definition: position = position with castling and en passant information, diagram = position without castling and en passant information. %C A019319 Even though the sequence may be infinite (if none of the rules for draw is ever invoked by any of the players), the sequence becomes constant from a given rank n on, since it is increasing (I conjecture - even though some positions available at the n-th move might not be available on the (1+n)-th move) and bounded, thus it has a limit. The challenge is now to find this limit (or at least nontrivial upper bounds) and the rank from which on the sequence becomes constant. - M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Feb 15 2008 %D A019319 Bernd Schwarzkopf, ''Die ersten Z"uge'' (The First Moves), Problemkiste (No.92, April 1994, p. 142-143). %H A019319 F. Labelle, Statistics on chess positions %H A019319 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %H A019319 Index entries for sequences related to number of chess games %Y A019319 Cf. A083276, A048987, A090051. %Y A019319 Cf. also A006494, A079485, A019319. %Y A019319 Sequence in context: A075843 A090051 A089957 this_sequence A083276 A057745 A009964 %Y A019319 Adjacent sequences: A019316 A019317 A019318 this_sequence A019320 A019321 A019322 %K A019319 nonn,hard,nice %O A019319 0,2 %A A019319 Bernd Schwarzkopf (schwarzkopf(AT)uni-duesseldorf.de) %E A019319 More terms from Richard Bean (rwb(AT)eskimo.com), Jun 02 2002 %E A019319 a(6)-a(8) from Francois Labelle (flab(AT)cs.berkeley.edu), Jan 19 2004 Search completed in 0.001 seconds