login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A304767
T(n,k)=Number of nXk 0..1 arrays with every element unequal to 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.
7
0, 0, 0, 0, 3, 0, 0, 5, 5, 0, 0, 18, 16, 18, 0, 0, 61, 103, 103, 61, 0, 0, 209, 609, 1321, 609, 209, 0, 0, 702, 3680, 14831, 14831, 3680, 702, 0, 0, 2381, 22187, 172574, 316639, 172574, 22187, 2381, 0, 0, 8069, 133917, 1999511, 6978743, 6978743, 1999511
OFFSET
1,5
COMMENTS
Table starts
.0....0......0.........0...........0..............0................0
.0....3......5........18..........61............209..............702
.0....5.....16.......103.........609...........3680............22187
.0...18....103......1321.......14831.........172574..........1999511
.0...61....609.....14831......316639........6978743........153265405
.0..209...3680....172574.....6978743......292676592......12219307955
.0..702..22187...1999511...153265405....12219307955.....969267512820
.0.2381.133917..23203301..3370551763...510976436144...77018325396680
.0.8069.808316.269239457.74123574757.21366609684109.6119460744287122
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) +2*a(n-3) -2*a(n-4) -4*a(n-5) for n>6
k=3: [order 13] for n>15
k=4: [order 31] for n>32
EXAMPLE
Some solutions for n=5 k=4
..0..0..0..1. .0..1..0..0. .0..1..1..0. .0..1..0..0. .0..1..1..0
..1..1..1..0. .0..1..1..1. .1..1..0..1. .1..1..1..1. .1..0..1..1
..0..1..1..1. .0..0..0..1. .0..0..0..0. .0..0..0..1. .0..1..0..1
..1..1..0..1. .1..1..1..0. .1..0..1..1. .1..0..1..0. .1..0..0..0
..0..0..1..0. .0..1..0..1. .0..1..1..0. .0..1..1..0. .0..1..1..1
CROSSREFS
Column 2 is A303684.
Sequence in context: A305457 A305022 A316686 * A316511 A317465 A051174
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, May 18 2018
STATUS
approved