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A240433
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 two plus the sum of the elements diagonally to its northwest, modulo 4
6
2, 2, 2, 4, 6, 4, 4, 24, 24, 4, 8, 58, 206, 58, 8, 8, 236, 970, 970, 236, 8, 16, 566, 8084, 9036, 8084, 566, 16, 16, 2322, 38406, 150350, 150350, 38406, 2322, 16, 32, 5578, 319164, 1404008, 5087802, 1404008, 319164, 5578, 32, 32, 22912, 1514122, 23414762
OFFSET
1,1
COMMENTS
Table starts
..2.....2........4...........4..............8...............8...............16
..2.....6.......24..........58............236.............566.............2322
..4....24......206.........970...........8084...........38406...........319164
..4....58......970........9036.........150350.........1404008.........23414762
..8...236.....8084......150350........5087802........94860720.......3184383016
..8...566....38406.....1404008.......94860720......3523795084.....237034323164
.16..2322...319164....23414762.....3184383016....237034323164...32020507274002
.16..5578..1514122...218412550....59125702284...8779074387924.2372829502697230
.32.22912.12567490..3639548326..1979684295626.589446737374098
.32.55054.59600672.33928317272.36705060609854
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-2)
k=2: a(n) = 12*a(n-2) -24*a(n-4) +31*a(n-6) -16*a(n-8)
k=3: [order 48]
EXAMPLE
Some solutions for n=4 k=4
..3..1..1..3....1..3..3..1....1..3..3..1....1..3..3..1....1..3..3..1
..1..2..2..2....3..2..2..0....3..2..2..0....3..2..2..0....3..0..2..2
..1..2..1..3....1..0..0..0....3..0..0..0....3..2..0..2....3..0..2..0
..3..2..3..2....3..2..0..3....1..2..2..0....1..0..2..0....1..0..2..0
CROSSREFS
Column 1 is A016116(n+1)
Sequence in context: A152968 A222177 A342271 * A217637 A231515 A231544
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Apr 04 2014
STATUS
approved