A240291 Number of nX3 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4

8, 26, 206, 974, 8064, 38252, 316962, 1502948, 12468758, 59122266, 490548594, 2326075252, 19300603720, 91520046552, 759392572070, 3600913438102, 29878821186710, 141680483207634, 1175603702913842, 5574521174572456

Offset

1,1

Comments

Column 3 of A240295

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>50

Example

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

Crossrefs

Sequence in context: A223312 A194997 A089064 * A203635 A000810 A171740

Adjacent sequences: A240288 A240289 A240290 * A240292 A240293 A240294

Keyword

nonn

Author

R. H. Hardin, Apr 03 2014

Status

approved