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A316876
T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1, 2, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
7
1, 2, 2, 4, 8, 4, 8, 23, 23, 8, 16, 65, 99, 65, 16, 32, 192, 425, 425, 192, 32, 64, 569, 1877, 2931, 1877, 569, 64, 128, 1709, 8333, 19363, 19363, 8333, 1709, 128, 256, 5162, 36900, 129974, 191678, 129974, 36900, 5162, 256, 512, 15663, 163433, 871345, 1956634
OFFSET
1,2
COMMENTS
Table starts
...1.....2......4........8.........16...........32............64
...2.....8.....23.......65........192..........569..........1709
...4....23.....99......425.......1877.........8333.........36900
...8....65....425.....2931......19363.......129974........871345
..16...192...1877....19363.....191678......1956634......19933839
..32...569...8333...129974....1956634.....30894538.....486546897
..64..1709..36900...871345...19933839....486546897...11836970493
.128..5162.163433..5848852..202681853...7638934647..286716424150
.256.15663.724406.39278049.2064146570.120283055361.6977675255288
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) +3*a(n-2) -6*a(n-3) -8*a(n-4) for n>5
k=3: [order 16] for n>17
k=4: [order 56] for n>58
EXAMPLE
Some solutions for n=5 k=4
..0..0..1..1. .0..0..0..1. .0..0..0..0. .0..0..0..0. .0..1..1..1
..0..1..1..1. .0..0..0..0. .0..1..1..0. .0..1..1..1. .0..0..1..1
..1..0..0..1. .0..1..0..0. .0..1..0..0. .1..0..0..1. .1..1..1..1
..1..1..0..0. .1..0..1..1. .0..0..1..1. .1..1..1..1. .1..0..1..1
..0..1..0..0. .1..1..1..1. .1..1..1..1. .0..1..1..0. .0..1..1..1
CROSSREFS
Column 1 is A000079(n-1).
Column 2 is A304304.
Sequence in context: A317125 A305593 A317011 * A317604 A038208 A240484
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jul 15 2018
STATUS
approved