|
|
A187165
|
|
Number of 4-step self-avoiding walks on an n X n X n cube summed over all starting positions.
|
|
2
|
|
|
0, 96, 1104, 3984, 9612, 18888, 32712, 51984, 77604, 110472, 151488, 201552, 261564, 332424, 415032, 510288, 619092, 742344, 880944, 1035792, 1207788, 1397832, 1606824, 1835664, 2085252, 2356488, 2650272, 2967504, 3309084, 3675912, 4068888
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 150*n^3 - 426*n^2 + 312*n - 48 for n>2.
G.f.: 12*x^2*(8 + 60*x + 12*x^2 - 7*x^3 + 2*x^4) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>6.
(End)
|
|
EXAMPLE
|
A solution for 2 X 2 X 2:
..2..0.....3..4
..1..0.....0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|