A240317 Number of nX3 0..3 arrays with no element equal to two plus the sum of elements to its left or two plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4

4, 18, 172, 866, 7326, 35042, 291982, 1387224, 11520638, 54650290, 453546794, 2150825840, 17847352698, 84630769202, 702236000852, 3329901981396, 27630151135038, 131017792653932, 1087129854047788, 5154993778435048

Offset

1,1

Comments

Column 3 of A240321

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)

Example

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

Crossrefs

Sequence in context: A239839 A367486 A156870 * A145075 A058924 A260970

Adjacent sequences: A240314 A240315 A240316 * A240318 A240319 A240320

Keyword

nonn

Author

R. H. Hardin, Apr 03 2014

Status

approved