A184224 Half the number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock diagonal sum differing from its antidiagonal sum by more than 3.

57, 411, 2318, 14641, 88103, 541936, 3302001, 20204829, 123402988, 754319381, 4609217629, 28168842830, 172139309061, 1051973256999, 6428702835542, 39286618550317, 240084864227147, 1467186858794824, 8966146857909117

Offset

1,1

Comments

Column 2 of A184231.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 6*a(n-1) + 7*a(n-2) - 42*a(n-3) + 17*a(n-4) + 24*a(n-5) - 12*a(n-6).

Empirical g.f.: x*(57 + 69*x - 547*x^2 + 250*x^3 + 324*x^4 - 168*x^5) / (1 - 6*x - 7*x^2 + 42*x^3 - 17*x^4 - 24*x^5 + 12*x^6). - Colin Barker, Apr 12 2018

Example

Some solutions for 5 X 3:
..0..1..0....3..0..3....0..3..0....2..0..3....2..3..0....3..0..2....2..0..3
..3..0..3....1..3..0....2..0..3....0..3..0....3..0..2....0..3..1....0..3..2
..2..3..1....3..1..3....1..3..0....3..0..2....1..3..1....3..0..3....1..0..3
..3..0..2....0..3..0....2..0..2....0..3..0....3..0..2....1..3..1....0..3..1
..1..3..1....3..1..3....1..3..1....2..0..1....0..2..0....2..0..3....2..0..2

Crossrefs

Cf. A184231.

Sequence in context: A237360 A076459 A268260 * A337629 A218812 A290779

Adjacent sequences: A184221 A184222 A184223 * A184225 A184226 A184227

Keyword

nonn

Author

R. H. Hardin, Jan 10 2011

Status

approved