A252536 Number of (4+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

535, 426, 610, 790, 1592, 2440, 3160, 6368, 9760, 12640, 25472, 39040, 50560, 101888, 156160, 202240, 407552, 624640, 808960, 1630208, 2498560, 3235840, 6520832, 9994240, 12943360, 26083328, 39976960, 51773440, 104333312, 159907840

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-3) for n>5.

Empirical g.f.: x*(535 + 426*x + 610*x^2 - 1350*x^3 - 112*x^4) / (1 - 4*x^3). - Colin Barker, Dec 04 2018

Example

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

Crossrefs

Row 4 of A252532.

Sequence in context: A077085 A165989 A183598 * A067723 A252275 A059949

Adjacent sequences: A252533 A252534 A252535 * A252537 A252538 A252539

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved