A251678 Number of (n+2)X(4+2) 0..2 arrays with no row, column, diagonal or antidiagonal in any 3X3 subblock summing to 2 or 4

2257, 5065, 16467, 64309, 264983, 1116829, 4748285, 20262955, 86674549, 370897287, 1587178279, 6793752837, 29083759187, 124506509193, 533008374225, 2281819402087, 9768583944333, 41819863365883, 179033174453907

Offset

1,1

Comments

Column 4 of A251682

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -4*a(n-2) +20*a(n-3) -52*a(n-4) -71*a(n-5) -88*a(n-6) +18*a(n-7) +1320*a(n-8) +1257*a(n-9) -181*a(n-10) -6879*a(n-11) -11550*a(n-12) +5548*a(n-13) +22299*a(n-14) +34495*a(n-15) -2321*a(n-16) -60516*a(n-17) -74685*a(n-18) -32216*a(n-19) +139323*a(n-20) +165997*a(n-21) +33867*a(n-22) -200557*a(n-23) -240141*a(n-24) +8357*a(n-25) +153626*a(n-26) +134084*a(n-27) -39350*a(n-28) -86744*a(n-29) +83068*a(n-30) +117432*a(n-31) +2542*a(n-32) -255689*a(n-33) -227960*a(n-34) +81803*a(n-35) +313563*a(n-36) +315476*a(n-37) +52784*a(n-38) -112762*a(n-39) -153077*a(n-40) -96828*a(n-41) -39570*a(n-42) -23470*a(n-43) -6008*a(n-44) -2912*a(n-45) +2604*a(n-46) +2560*a(n-47) +1224*a(n-48) +648*a(n-49) -288*a(n-50) for n>54

Example

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

Crossrefs

Sequence in context: A222951 A035873 A257825 * A231245 A046168 A251509

Adjacent sequences: A251675 A251676 A251677 * A251679 A251680 A251681

Keyword

nonn

Author

R. H. Hardin, Dec 06 2014

Status

approved