A240390 Number of nX3 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4

1, 7, 32, 258, 1232, 10291, 48826, 405404, 1922824, 15957927, 75674424, 627937288, 2977619007, 24707220314, 117158008335, 972128626445, 4609679165199, 38249153789915, 181371291266288, 1504941221689915, 7136186544470695

Offset

1,2

Comments

Column 3 of A240394

Links

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

Formula

Empirical: a(n) = 63*a(n-2) -1109*a(n-4) +7143*a(n-6) -395*a(n-8) -201246*a(n-10) +762860*a(n-12) +347011*a(n-14) -7366154*a(n-16) +11744674*a(n-18) +3758987*a(n-20) +10095295*a(n-22) -126415852*a(n-24) +204390541*a(n-26) -65238786*a(n-28) -59211883*a(n-30) -114625640*a(n-32) +381020006*a(n-34) -342073760*a(n-36) +16725276*a(n-38) +181283664*a(n-40) -110895680*a(n-42) +16492080*a(n-44) +1175136*a(n-46) +390464*a(n-48) for n>49

Example

Some solutions for n=4
..3..0..0....3..0..0....3..0..0....3..0..0....3..0..0....3..0..0....3..0..0
..3..0..0....3..0..0....3..0..0....1..0..0....1..2..0....1..3..3....3..0..0
..1..2..2....1..2..0....1..2..0....3..0..2....3..2..0....3..1..2....1..0..0
..1..2..0....1..2..0....3..0..2....1..0..2....1..3..3....1..3..3....1..2..2

Crossrefs

Sequence in context: A302995 A188331 A177766 * A024093 A110323 A288721

Adjacent sequences: A240387 A240388 A240389 * A240391 A240392 A240393

Keyword

nonn

Author

R. H. Hardin, Apr 04 2014

Status

approved