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A240347
T(n,k)=Number of nXk 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it or three plus the sum of the elements diagonally to its northwest, modulo 4
6
2, 4, 4, 8, 18, 8, 16, 78, 78, 16, 32, 334, 722, 334, 32, 64, 1418, 6376, 6376, 1418, 64, 128, 6002, 55680, 115194, 55680, 6002, 128, 256, 25374, 483926, 2044806, 2044806, 483926, 25374, 256, 512, 107230, 4195892, 36002110, 73440130, 36002110, 4195892
OFFSET
1,1
COMMENTS
Table starts
....2.......4..........8............16..............32..............64
....4......18.........78...........334............1418............6002
....8......78........722..........6376...........55680..........483926
...16.....334.......6376........115194.........2044806........36002110
...32....1418......55680.......2044806........73440130......2607237326
...64....6002.....483926......36002110......2607237326....186214281670
..128...25374....4195892.....631121148.....92003133794..13200773101956
..256..107230...36331704...11038084086...3236101836296.932020621734728
..512..453098..314419494..192823850946.113624636162418
.1024.1914498.2720368268.3366365227614
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 6*a(n-1) -7*a(n-2) -4*a(n-3) +8*a(n-4)
k=3: [order 23]
EXAMPLE
Some solutions for n=4 k=4
..2..0..0..0....0..0..0..0....2..0..0..2....0..0..0..2....2..2..2..0
..0..0..2..0....0..0..2..2....0..3..2..0....2..0..0..0....2..2..2..0
..2..0..2..2....2..2..2..2....2..1..1..2....2..2..0..0....0..3..2..0
..0..0..0..2....2..0..2..3....2..2..2..2....2..0..0..0....2..2..2..2
CROSSREFS
Column 1 is A000079
Sequence in context: A291778 A089887 A161816 * A160124 A295293 A080007
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Apr 04 2014
STATUS
approved