A252310 Number of (5+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7

2587, 2350, 3669, 5117, 9368, 15444, 22521, 43870, 72344, 109721, 229454, 377280, 602057, 1358574, 2223120, 3723881, 8973230, 14621424, 25440425, 64229166, 104350128, 186159401, 483655214, 784380720, 1419895337, 3748625454

Offset

1,1

Comments

Row 5 of A252305

Links

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

Formula

Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>21

Example

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

Crossrefs

Sequence in context: A200711 A235950 A260840 * A236351 A250241 A252152

Adjacent sequences: A252307 A252308 A252309 * A252311 A252312 A252313

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved