A252521 Number of (n+2) X (6+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 2 4 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 2 4 6 or 7.

1471, 5214, 21510, 47308, 268555, 1215491, 2662952, 15755867, 73792188, 160605830, 977103095, 4668722734, 10119572634, 62609075589, 302574704284, 654293895244, 4086229186201, 19870347822346, 42913053749386

Offset

1,1

Comments

Column 6 of A252523.

Links

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

Formula

Empirical: a(n) = 123*a(n-3) -4692*a(n-6) +69418*a(n-9) -496012*a(n-12) +1948488*a(n-15) -4564660*a(n-18) +6732956*a(n-21) -6502868*a(n-24) +4253029*a(n-27) -1930703*a(n-30) +601744*a(n-33) -118886*a(n-36) +12592*a(n-39) -528*a(n-42) for n>50.

Example

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

Crossrefs

Cf. A252523.

Sequence in context: A083526 A068753 A255735 * A237379 A237144 A187310

Adjacent sequences: A252518 A252519 A252520 * A252522 A252523 A252524

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved