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A240327
T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4
6
2, 2, 2, 4, 5, 4, 6, 17, 17, 6, 8, 37, 116, 37, 8, 14, 80, 455, 455, 80, 14, 20, 213, 1677, 3374, 1677, 213, 20, 30, 443, 8091, 21455, 21455, 8091, 443, 30, 48, 1028, 28448, 189549, 247187, 189549, 28448, 1028, 48, 70, 2511, 117304, 1190246, 3898804
OFFSET
1,1
COMMENTS
Table starts
..2....2.......4.........6............8............14............20
..2....5......17........37...........80...........213...........443
..4...17.....116.......455.........1677..........8091.........28448
..6...37.....455......3374........21455........189549.......1190246
..8...80....1677.....21455.......247187.......3898804......43979526
.14..213....8091....189549......3898804.....113751796....2343565571
.20..443...28448...1190246.....43979526....2343565571...88562956949
.30.1028..117304...8903613....602874070...58754628922.4085612680937
.48.2511..513841..70945972...8649395684.1550370290554
.70.5370.1871262.460466581.101952716878
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = a(n-2) +2*a(n-3)
k=2: [order 13] for n>14
EXAMPLE
Some solutions for n=4 k=4
..3..2..3..2....3..2..3..3....2..3..3..2....3..2..2..2....3..2..3..2
..2..1..2..3....2..1..2..2....3..0..1..3....2..1..1..1....2..3..2..1
..3..1..3..2....3..2..2..0....3..1..1..2....3..0..2..2....3..0..0..2
..2..3..2..2....3..2..2..2....2..3..3..2....3..2..2..2....3..2..0..0
CROSSREFS
Column 1 is A239851
Sequence in context: A151680 A231351 A024681 * A308771 A007495 A122385
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Apr 03 2014
STATUS
approved