|
|
A252154
|
|
Number of (n+2)X(5+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7
|
|
1
|
|
|
5577, 4732, 9572, 15460, 29276, 57271, 114243, 225966, 451186, 898886, 1796742, 3567622, 7180566, 14252982, 28550806, 57071990, 114226230, 227100406, 457805238, 909211446, 1822429366, 3645696566, 7298665782, 14515253302
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = -a(n-1) +2*a(n-2) +14*a(n-3) +14*a(n-4) -28*a(n-5) -56*a(n-6) -56*a(n-7) +112*a(n-8) +64*a(n-9) +64*a(n-10) -128*a(n-11) for n>16
|
|
EXAMPLE
|
Some solutions for n=4
..3..3..2..0..2..0..3....3..2..0..2..0..2..3....3..2..0..2..3..3..3
..0..2..0..2..0..2..0....3..0..2..0..2..0..2....2..0..2..0..2..0..2
..2..0..2..0..2..0..2....3..2..0..2..0..2..0....0..2..0..2..0..2..3
..0..2..0..2..0..2..0....2..0..2..0..2..0..2....2..0..2..0..2..0..3
..2..0..2..0..2..0..2....0..2..0..2..0..2..3....3..2..0..2..0..2..3
..3..3..3..3..3..2..0....3..0..2..0..2..3..3....3..3..3..3..2..0..3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|