A252467 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 5 6 or 8

716, 682, 813, 1463, 3497, 9056, 24331, 66366, 182232, 501727, 1381625, 3805197, 10482896, 28880351, 79562832, 219191402, 603866771, 1663632701, 4583248473, 12626699802, 34786145839, 95834674648, 264021358176, 727370136753

Offset

1,1

Comments

Column 2 of A252473

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +7*a(n-3) +7*a(n-4) +7*a(n-5) +4*a(n-6) -2*a(n-7) -4*a(n-8) -9*a(n-9) -8*a(n-10) -7*a(n-11) -3*a(n-12) +a(n-13) +3*a(n-14) +2*a(n-15) +a(n-16) for n>21

Example

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

Crossrefs

Sequence in context: A208407 A208414 A214237 * A233629 A151631 A183841

Adjacent sequences: A252464 A252465 A252466 * A252468 A252469 A252470

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved