A233677 Number of (n+1)X(3+1) 0..3 arrays with every 2X2 subblock having the sum of the squares of the edge differences equal to 6

648, 4448, 28544, 216592, 1500800, 11482368, 81243904, 617735680, 4416166400, 33345630720, 240057191680, 1802241148160, 13042092095744, 97474927920896, 708192185963776, 5274586398563072, 38438858246173952, 285526308610159360

Offset

1,1

Comments

Column 3 of A233682

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +70*a(n-2) -332*a(n-3) -1384*a(n-4) +6780*a(n-5) +11520*a(n-6) -61568*a(n-7) -45216*a(n-8) +280096*a(n-9) +84864*a(n-10) -653696*a(n-11) -81664*a(n-12) +762880*a(n-13) +41984*a(n-14) -397312*a(n-15) -8192*a(n-16) +65536*a(n-17)

Example

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

Crossrefs

Sequence in context: A006914 A337313 A204392 * A200938 A165611 A282334

Adjacent sequences: A233674 A233675 A233676 * A233678 A233679 A233680

Keyword

nonn

Author

R. H. Hardin, Dec 14 2013

Status

approved