|
|
A268113
|
|
Number of legal positions in Go played on an n X n+1 grid (each group must have at least one liberty).
|
|
3
|
|
|
5, 489, 321689, 1840058693, 93332304864173, 41945191530093646965, 166931297609667912727898521, 5882748866432370655674372752123193, 1835738613899845421140262364853644706891109, 5072588588647327658457862518216696854885169490987149
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Upper bounded by 3^{n*(n+1)}.
|
|
LINKS
|
John Tromp, Table of n, a(n) for n = 1..19
John Tromp, Number of legal Go positions
J. Tromp and G. Farnebäck, Combinatorics of Go, Lecture Notes in Computer Science, 4630, 84-99, 2007.
|
|
EXAMPLE
|
For n=1 the 5 legal 1x2 boards are .. X. O. .X .O
|
|
CROSSREFS
|
Almost-square version of A094777.
Sequence in context: A206502 A198249 A160363 * A308132 A352181 A152513
Adjacent sequences: A268110 A268111 A268112 * A268114 A268115 A268116
|
|
KEYWORD
|
nonn,hard
|
|
AUTHOR
|
John Tromp, Jan 26 2016
|
|
STATUS
|
approved
|
|
|
|