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.

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

R. H. Hardin, Table of n, a(n) for n = 1..84

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

Adjacent sequences: A270147 A270148 A270149 * A270151 A270152 A270153

Keyword

nonn,tabl

Author

R. H. Hardin, Mar 12 2016

Status

approved