A251646 Number of (n+2)X(2+2) 0..3 arrays with no row, column, diagonal or antidiagonal in any 3X3 subblock summing to 0 2 4 5 7 or 9

448, 908, 1928, 4008, 10248, 22904, 49956, 129296, 300656, 689192, 1792064, 4317696, 10331264, 26936064, 66797136, 165179552, 431375936, 1092206912, 2762577872, 7222018464, 18536302352, 47560605216, 124411054752, 322001817152

Offset

1,1

Comments

Column 2 of A251652

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -2*a(n-2) +4*a(n-3) -36*a(n-4) +22*a(n-5) +59*a(n-6) -40*a(n-7) -20*a(n-8) +10*a(n-9) for n>15

Example

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

Crossrefs

Sequence in context: A153486 A062040 A093786 * A235177 A346514 A194648

Adjacent sequences: A251643 A251644 A251645 * A251647 A251648 A251649

Keyword

nonn

Author

R. H. Hardin, Dec 06 2014

Status

approved