A252339 Number of (n+2)X(4+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 2 3 or 4

538, 2242, 10154, 43708, 184434, 783852, 3338572, 14229718, 60618068, 258032046, 1098638058, 4679093984, 19926283674, 84850464484, 361322860036, 1538671968330, 6552292795660, 27902184864342, 118818430207970

Offset

1,1

Comments

Column 4 of A252343

Links

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

Formula

Empirical: a(n) = a(n-1) +6*a(n-2) +20*a(n-3) +54*a(n-4) +38*a(n-5) -41*a(n-6) -191*a(n-7) -285*a(n-8) +296*a(n-9) +753*a(n-10) -160*a(n-11) -791*a(n-12) -99*a(n-13) +334*a(n-14) +98*a(n-15) -18*a(n-16) +54*a(n-17) -3*a(n-18) -35*a(n-19) +3*a(n-20) -12*a(n-21) -7*a(n-22) +4*a(n-23) for n>25

Example

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

Crossrefs

Sequence in context: A235780 A235785 A235561 * A224742 A231194 A367525

Adjacent sequences: A252336 A252337 A252338 * A252340 A252341 A252342

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved