A252581 Number of (7+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.

8279, 39419, 275252, 802760, 7115253, 53055996, 155864925, 1380518004, 10339904588, 30371389585, 268585630512, 2020072809256, 5932838682650, 52395775636832, 395480404508430, 1161448118532776, 10243694081474738

Offset: 1

Author

R. H. Hardin, Dec 18 2014

Keywords

• nonn

Comments

Row 7 of A252574

Examples

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

Links

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

Formula

Empirical: a(n) = 414*a(n-3) -49716*a(n-6) +1528047*a(n-9) -30967009*a(n-12) [phone]*a(n-15) -3431389746*a(n-18) [phone]*a(n-21) -18662541672*a(n-24) [phone]*a(n-27) -9970599024*a(n-30) [phone]*a(n-33) -681198336*a(n-36) for n>45