A240035 Number of nX4 0..2 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 3

4, 4, 16, 18, 52, 62, 162, 204, 530, 672, 1736, 2198, 5706, 7202, 18780, 23604, 61718, 77292, 202468, 252872, 663072, 826512, 2168300, 2698978, 7082068, 8806712, 23110072, 28718278, 75360086, 93603560, 245616936, 304976256, 800224510

Offset

1,1

Comments

Column 4 of A240039

Links

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

Formula

Empirical: a(n) = 11*a(n-2) -49*a(n-4) +117*a(n-6) -177*a(n-8) +214*a(n-10) -239*a(n-12) +207*a(n-14) -135*a(n-16) +108*a(n-18) -82*a(n-20) +29*a(n-22) -3*a(n-24) for n>27

Example

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

Crossrefs

Sequence in context: A231940 A129884 A137725 * A321677 A223819 A082649

Adjacent sequences: A240032 A240033 A240034 * A240036 A240037 A240038

Keyword

nonn

Author

R. H. Hardin, Mar 31 2014

Status

approved