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A270150
T(n,k)=Number of nXk 0..7 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling seven exactly once.
6
0, 8, 8, 112, 1440, 112, 1176, 85056, 85056, 1176, 10976, 4126368, 24250368, 4126368, 10976, 96040, 182257536, 5750902944, 5750902944, 182257536, 96040, 806736, 7623445344, 1246566350496, 6697695002208, 1246566350496, 7623445344, 806736
OFFSET
1,2
COMMENTS
Table starts
.....0..........8.............112................1176....................10976
.....8.......1440...........85056.............4126368................182257536
...112......85056........24250368..........5750902944............1246566350496
..1176....4126368......5750902944.......6697695002208.........7142783643783792
.10976..182257536...1246566350496....7142783643783792.....37516051668350707200
.96040.7623445344.256330155581328.7232246139319438944.187171034679828236009184
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 14*a(n-1) -49*a(n-2)
k=2: a(n) = 66*a(n-1) -1021*a(n-2) -2244*a(n-3) -1156*a(n-4) for n>5
k=3: [order 10] for n>11
k=4: [order 30] for n>31
EXAMPLE
Some solutions for n=2 k=4
..0..4..7..5. .0..2..6..2. .0..3..1..1. .0..0..4..7. .0..2..7..6
..0..4..2..1. .0..5..0..6. .0..6..5..1. .0..0..4..0. .4..2..4..0
CROSSREFS
Column 1 is A270111.
Sequence in context: A192386 A119932 A270118 * A065241 A255006 A074191
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Mar 12 2016
STATUS
approved