A196424 Number of nX2 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself

3, 23, 123, 809, 5274, 33923, 219807, 1424725, 9226721, 59782080, 387322045, 2509377827, 16258011561, 105333834791, 682445646554, 4421489543317, 28646335313891, 185596395723437, 1202458284920023, 7790592650792034

Offset

1,1

Comments

Column 2 of A196430

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +22*a(n-2) +24*a(n-3) -86*a(n-4) -296*a(n-5) -126*a(n-6) +428*a(n-7) +420*a(n-8) +239*a(n-9) +92*a(n-10) -147*a(n-11) +22*a(n-12) +26*a(n-13) -13*a(n-14) +5*a(n-15)

Example

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

Crossrefs

Sequence in context: A081628 A267656 A122883 * A091055 A154648 A031970

Adjacent sequences: A196421 A196422 A196423 * A196425 A196426 A196427

Keyword

nonn

Author

R. H. Hardin Oct 02 2011

Status

approved