A252082 Number of (n+2)X(2+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 1 3 or 4

130, 322, 943, 2595, 7089, 19910, 55703, 155266, 434540, 1216413, 3402605, 9524573, 26668604, 74669305, 209114056, 585748112, 1640928543, 4597673521, 12884229439, 36111198006, 101225635011, 283795383806, 795763649138, 2231651536147

Offset

1,1

Comments

Column 2 of A252088

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -2*a(n-2) +7*a(n-3) -29*a(n-4) -11*a(n-5) -10*a(n-6) +60*a(n-7) +72*a(n-8) +39*a(n-9) -48*a(n-10) -69*a(n-11) -75*a(n-12) -36*a(n-13) -9*a(n-14) +30*a(n-15) +49*a(n-16) +44*a(n-17) +14*a(n-18) -7*a(n-19) -13*a(n-20) -7*a(n-21) -2*a(n-22) for n>23

Example

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

Crossrefs

Sequence in context: A238194 A252263 A252361 * A253044 A253037 A281209

Adjacent sequences: A252079 A252080 A252081 * A252083 A252084 A252085

Keyword

nonn

Author

R. H. Hardin, Dec 13 2014

Status

approved