A252578 Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.

1469, 3286, 10885, 25882, 107651, 395500, 959944, 4006901, 14816006, 35925302, 149837853, 555593556, 1346798430, 5611997409, 20856438080, 50548611374, 210462210945, 783856206336, 1899488450222, 7902528627913, 29493363498624

Offset: 1

Author

R. H. Hardin, Dec 18 2014

Keywords

• nonn

Comments

Row 4 of A252574

Examples

			Some solutions for n=4
..2..3..2..1..3..2....0..2..0..0..1..0....0..0..2..0..0..1....0..0..2..0..0..2
..0..0..2..0..0..2....0..0..1..0..0..1....3..1..2..3..2..2....3..1..2..3..2..1
..2..0..0..2..0..0....3..2..2..3..2..2....0..2..0..0..1..0....0..2..0..0..2..0
..2..3..2..2..3..2....0..1..0..0..2..0....0..0..1..0..0..2....0..0..2..0..0..2
..0..0..1..0..0..2....0..0..2..0..0..2....3..2..2..3..2..1....0..1..1..3..2..1
..1..0..0..1..0..0....3..2..1..3..1..2....0..1..0..0..2..0....0..2..0..0..2..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 78*a(n-3) -1701*a(n-6) +7656*a(n-9) -30460*a(n-12) +70284*a(n-15) -70416*a(n-18) +25968*a(n-21) -1408*a(n-24) for n>31