|
|
A077482
|
|
Number of self-avoiding walks on square lattice trapped after n steps.
|
|
14
|
|
|
1, 2, 11, 25, 95, 228, 752, 1860, 5741, 14477, 42939, 109758, 317147, 818229, 2322512, 6030293, 16900541, 44079555, 122379267, 320227677, 882687730, 2315257359, 6346076015, 16675422679, 45502168379, 119728011251, 325510252108, 857400725204
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
7,2
|
|
COMMENTS
|
Only 1/8 of all possible walks is counted by selecting the first step in +x direction and requiring the first step changing y to be positive.
|
|
REFERENCES
|
|
|
LINKS
|
|
|
EXAMPLE
|
a(7) = 1 because there is only 1 self-trapping walk with 7 steps: (0,0)(1,0)(1,1)(1,2)(0,2)(-1,2)(-1,1)(0,1); a(8) = 2 because there are 2 self-trapping walks with 8 steps: (0,0)(1,0)(2,0)(2,1)(2,2)(1,2)(0,2)(0,1)(1,1) and (0,0)(1,0)(1,1)(2,1)(3,1)(3,0)(3,-1)(2,-1)(2,0).
|
|
PROG
|
FORTRAN program provided at given link.
|
|
CROSSREFS
|
|
|
KEYWORD
|
more,nonn,walk
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|