A252247 Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 3 5 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 3 5 6 or 7

318, 260, 278, 352, 463, 616, 847, 1160, 1625, 2281, 3237, 4631, 6575, 9496, 13664, 19579, 28429, 41049, 59172, 86036, 124646, 180255, 262364, 381099, 552201, 804746, 1170960, 1699487, 2479568, 3612216, 5250764, 7667560, 11180674, 16274784

Offset

1,1

Comments

Column 1 of A252254

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +7*a(n-3) -a(n-4) -11*a(n-5) -19*a(n-6) +4*a(n-7) +21*a(n-8) +26*a(n-9) -4*a(n-10) -18*a(n-11) -19*a(n-12) +a(n-13) +7*a(n-14) +7*a(n-15) -a(n-17) -a(n-18) for n>25

Example

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

Crossrefs

Sequence in context: A058002 A252246 A252254 * A323327 A323328 A045272

Adjacent sequences: A252244 A252245 A252246 * A252248 A252249 A252250

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved