A184101 T(n,k)=One quarter the number of nXk toroidal 0..3 arrays with each element having the sum of its vertical neighbors equal to the sum of its horizontal neighbors

1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 4, 85, 4, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 484, 1, 4, 1, 1, 1, 85, 1, 1, 85, 1, 1, 1, 4, 1, 4, 3661, 4, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 85, 484, 1, 28900, 1, 484, 85, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 4, 1, 4, 137845, 4, 1, 4, 1, 4, 1, 1, 1

Offset

1,5

Comments

One quarter the number of solutions in 0..3 of a 1-d velocity-one wave equation utt=uxx on a periodic grid

Table starts

.1.1..1...1....1.....1......1.......1..1....1.1.....1.1.1..1.1.1

.1.4..1...4....1.....4......1.......4..1....4.1.....4.1.4..1.4

.1.1.85...1....1....85......1.......1.85....1.1....85.1.1.85

.1.4..1.484....1.....4......1.....484..1....4.1...484.1.4

.1.1..1...1.3661.....1......1.......1..1.3661.1.....1.1

.1.4.85...4....1.28900......1.......4.85....4.1.28900

.1.1..1...1....1.....1.137845.......1..1....1.1

.1.4..1.484....1.....4......1.1322500..1....4

.1.1.85...1....1....85......1.......1

.1.4..1...4.3661.....4......1

Links

R. H. Hardin, Table of n, a(n) for n = 1..144

Example

Some solutions for 9X3
..3..0..3....1..1..1....3..2..0....2..1..1....1..0..2....3..1..2....1..2..1
..3..3..0....0..1..2....1..1..3....2..2..0....2..1..0....0..3..3....1..2..1
..0..3..3....2..1..0....1..2..2....0..1..3....0..2..1....3..2..1....2..0..2
..3..0..3....1..1..1....3..2..0....2..1..1....1..0..2....3..1..2....1..2..1
..3..3..0....0..1..2....1..1..3....2..2..0....2..1..0....0..3..3....1..2..1
..0..3..3....2..1..0....1..2..2....0..1..3....0..2..1....3..2..1....2..0..2
..3..0..3....1..1..1....3..2..0....2..1..1....1..0..2....3..1..2....1..2..1
..3..3..0....0..1..2....1..1..3....2..2..0....2..1..0....0..3..3....1..2..1
..0..3..3....2..1..0....1..2..2....0..1..3....0..2..1....3..2..1....2..0..2

Crossrefs

Sequence in context: A204160 A360165 A336870 * A347176 A164561 A178764

Adjacent sequences: A184098 A184099 A184100 * A184102 A184103 A184104

Keyword

nonn,tabl

Author

R. H. Hardin Jan 09 2011

Status

approved