|
|
A206500
|
|
Number of nX3 0..7 arrays with no element equal to another within a city block distance of two, and new values 0..7 introduced in row major order
|
|
1
|
|
|
1, 4, 65, 3130, 178998, 10502458, 618242826, 36410671102, 2144479610070, 126304554589462, 7439032094765766, 438141046109721622, 25805450786659366998, 1519878816318690262678, 89517196729004371783830
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 55*a(n-1) +370*a(n-2) -8556*a(n-3) +15608*a(n-4) +70028*a(n-5) -175808*a(n-6) +98304*a(n-7) for n>9
|
|
EXAMPLE
|
Some solutions for n=4
..0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..2..3..0....2..3..0....2..3..0....3..4..0....2..3..4....2..3..4....2..3..4
..1..4..5....4..5..1....1..4..5....2..5..1....1..0..5....1..5..6....4..5..1
..5..0..1....1..0..4....5..2..1....0..3..6....3..4..2....3..4..7....6..2..3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|