A252195 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 7

585, 470, 669, 1313, 3201, 8526, 23265, 63626, 174878, 481751, 1326853, 3654591, 10068350, 27738291, 76416644, 210524622, 579990251, 1597852801, 4402028111, 12127445456, 33410714513, 92045405856, 253582052916, 698610194687

Offset

1,1

Comments

Column 2 of A252201

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
..3..3..3..3....3..3..3..3....3..3..3..2....3..3..2..3....2..1..1..0
..3..3..3..3....3..3..3..2....3..2..3..3....3..3..3..3....0..0..1..1
..3..3..3..3....3..3..3..3....3..3..3..3....3..3..3..3....0..1..0..0
..3..2..3..3....3..3..3..3....3..3..3..3....3..3..3..3....2..0..0..1
..3..3..3..3....2..3..3..2....2..3..3..3....3..3..3..2....2..1..1..0
..3..3..3..3....3..3..3..3....3..3..3..3....3..3..2..3....0..0..1..0

Crossrefs

Sequence in context: A235433 A205069 A187050 * A037995 A250627 A043428

Adjacent sequences: A252192 A252193 A252194 * A252196 A252197 A252198

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved