A252362 Number of (n+2) X (1+2) 0..3 arrays with every 3 X 3 subblock row, column, diagonal and antidiagonal sum not equal to 1 3 4 6 or 7.

130, 152, 282, 658, 1482, 3188, 6954, 15432, 34120, 74978, 164806, 363086, 800136, 1761810, 3878444, 8540376, 18808306, 41417594, 91200010, 200823828, 442228226, 973812608, 2144371120, 4721986338, 10398032398, 22896956750, 50420107128

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 3*a(n-3) + 4*a(n-4) + 4*a(n-5) + 2*a(n-6) for n>8.

Empirical g.f.: 2*x*(65 + 11*x + 65*x^2 - 7*x^3 - 76*x^4 - 134*x^5 - 102*x^6 - 16*x^7) / (1 - x - 3*x^3 - 4*x^4 - 4*x^5 - 2*x^6). - Colin Barker, Dec 03 2018

Example

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

Crossrefs

Column 1 of A252369.

Sequence in context: A025364 A294311 A252369 * A331629 A248943 A248649

Adjacent sequences: A252359 A252360 A252361 * A252363 A252364 A252365

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved