|
|
A252402
|
|
Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7
|
|
1
|
|
|
983, 774, 1515, 3302, 8346, 20998, 50675, 133296, 343447, 848007, 2263089, 5902801, 14734098, 39629269, 104070383, 261353804, 706017540, 1860981190, 4689050899, 12697106938, 33535406222, 84648673583, 229505457761, 606816472873
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 32*a(n-3) -310*a(n-6) +1291*a(n-9) -4641*a(n-12) +11713*a(n-15) -20535*a(n-18) +26754*a(n-21) -23045*a(n-24) +8109*a(n-27) +1127*a(n-30) -638*a(n-33) +162*a(n-36) -12*a(n-39) -7*a(n-42) +a(n-45) for n>48
|
|
EXAMPLE
|
Some solutions for n=4
..2..3..2..2..0....3..0..1..3..3....3..2..2..3..2....0..2..2..3..2
..3..3..1..3..3....3..2..2..0..2....2..3..2..2..3....2..3..2..2..0
..3..2..2..3..2....2..3..2..2..3....3..3..1..3..3....3..3..1..3..3
..2..3..2..2..3....0..3..1..3..3....3..2..2..3..2....0..2..2..0..2
..3..3..1..3..0....3..2..2..3..2....2..3..2..2..3....2..3..2..2..3
..0..2..2..3..2....2..0..2..2..0....3..3..1..3..3....3..3..1..3..3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|