|
|
A221552
|
|
Number of 2Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns
|
|
1
|
|
|
1, 10, 72, 503, 3517, 24546, 171268, 1194876, 8335964, 58154668, 405706565, 2830343128, 19745403738, 137750412592, 960992030353, 6704195338721, 46770663635910, 326287475880302, 2276288352727268, 15880133462880199
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 11*a(n-1) -25*a(n-2) -46*a(n-3) +164*a(n-4) +129*a(n-5) -513*a(n-6) -301*a(n-7) +913*a(n-8) +562*a(n-9) -943*a(n-10) -675*a(n-11) +513*a(n-12) +436*a(n-13) -128*a(n-14) -111*a(n-15) +17*a(n-16) +6*a(n-17)
|
|
EXAMPLE
|
Some solutions for n=3
..1..1..0....1..1..3....0..1..0....1..0..2....1..1..1....0..3..1....2..2..0
..1..3..0....0..0..1....1..3..1....1..1..1....1..2..0....0..2..0....1..1..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|