A252427 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 4 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 4 6 or 7.

915, 688, 914, 1801, 2993, 6164, 13139, 26670, 55677, 119785, 248291, 522400, 1128516, 2346628, 4950707, 10715161, 22309343, 47111547, 102054851, 212611950, 449193290, 973471926, 2028637174, 4287035224, 9292670275, 19367979783

Offset

1,1

Comments

Column 2 of A252433.

Links

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

Formula

Empirical: a(n) = 16*a(n-3) -74*a(n-6) +146*a(n-9) -294*a(n-12) +336*a(n-15) -316*a(n-18) +290*a(n-21) -119*a(n-24) +11*a(n-27) +6*a(n-30) -a(n-33) for n>37.

Example

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

Crossrefs

Cf. A252433.

Sequence in context: A286214 A189182 A365514 * A074887 A234993 A234764

Adjacent sequences: A252424 A252425 A252426 * A252428 A252429 A252430

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved