A252389 Number of (5+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.

785, 637, 799, 916, 1305, 1894, 2310, 3280, 4791, 5934, 8451, 12386, 15413, 21987, 32274, 40226, 57424, 84343, 105186, 150199, 220662, 275253, 393087, 577550, 720494, 1028976, 1511895, 1886150, 2693755, 3958042, 4937877, 7052203, 10362138

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-3) - 4*a(n-6) + a(n-9) for n>14.

Empirical g.f.: x*(785 + 637*x + 799*x^2 - 2224*x^3 - 1243*x^4 - 1302*x^5 + 1786*x^6 + 608*x^7 + 411*x^8 - 427*x^9 - 86*x^10 - x^11 + x^12 - 2*x^13) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

Example

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

Crossrefs

Row 5 of A252384.

Sequence in context: A151658 A231771 A366829 * A159896 A031734 A097776

Adjacent sequences: A252386 A252387 A252388 * A252390 A252391 A252392

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved