A252522 Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 4 6 or 7

2176, 9069, 39689, 96659, 581529, 2662952, 6486931, 38674076, 177771524, 432970668, 2576695286, 11849993914, 28861601874, 171722924036, 789791249282, 1923610959226, 11444904413552, 52638098030182, 128205198751454

Offset

1,1

Comments

Column 7 of A252523

Links

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

Formula

Empirical: a(n) = 86*a(n-3) -1415*a(n-6) +8680*a(n-9) -22666*a(n-12) +28036*a(n-15) -15888*a(n-18) +3168*a(n-21) for n>29

Example

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

Crossrefs

Sequence in context: A237303 A283346 A252348 * A159712 A186917 A185801

Adjacent sequences: A252519 A252520 A252521 * A252523 A252524 A252525

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved