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A184097 T(n,k)=Half the number of nXk toroidal binary arrays with each element having the sum of its vertical neighbors equal to the sum of its horizontal neighbors 2
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 7, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 18, 1, 2, 1, 1, 1, 7, 1, 1, 7, 1, 1, 1, 2, 1, 2, 31, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 7, 18, 1, 98, 1, 18, 7, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 127, 2, 1, 2, 1, 2, 1, 1, 1, 7, 1, 31, 7, 1, 1, 7, 31, 1, 7 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Half the number of solutions in 0..1 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...1.1....1...1.1.1...1..1

.1.2.1..2..1..2...1...2...1....2.1..2.1...2..1...2.1...2.1....2...1.2.1...2..1

.1.1.7..1..1..7...1...1...7....1.1..7.1...1..7...1.1...7.1....1...7.1.1...7..1

.1.2.1.18..1..2...1..18...1....2.1.18.1...2..1..18.1...2.1...18...1.2.1..18..1

.1.1.1..1.31..1...1...1...1...31.1..1.1...1.31...1.1...1.1...31...1.1.1...1.31

.1.2.7..2..1.98...1...2...7....2.1.98.1...2..7...2.1..98.1....2...7.2.1..98..1

.1.1.1..1..1..1.127...1...1....1.1..1.1.127..1...1.1...1.1....1.127.1.1...1..1

.1.2.1.18..1..2...1.450...1....2.1.18.1...2..1.450.1...2.1...18...1.2.1.450..1

.1.1.7..1..1..7...1...1.511....1.1..7.1...1..7...1.1.511.1....1...7.1.1...7..1

.1.2.1..2.31..2...1...2...1.1922.1..2.1...2.31...2.1...2.1.1922...1.2.1...2.31

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..840

EXAMPLE

Some solutions for 9X3

..1..0..0....0..0..1....1..1..0....0..1..0....1..0..1....1..1..0....0..0..1

..0..1..0....0..1..0....1..0..1....1..0..0....1..1..0....0..1..1....1..0..0

..0..0..1....1..0..0....0..1..1....0..0..1....0..1..1....1..0..1....0..1..0

..1..0..0....0..0..1....1..1..0....0..1..0....1..0..1....1..1..0....0..0..1

..0..1..0....0..1..0....1..0..1....1..0..0....1..1..0....0..1..1....1..0..0

..0..0..1....1..0..0....0..1..1....0..0..1....0..1..1....1..0..1....0..1..0

..1..0..0....0..0..1....1..1..0....0..1..0....1..0..1....1..1..0....0..0..1

..0..1..0....0..1..0....1..0..1....1..0..0....1..1..0....0..1..1....1..0..0

..0..0..1....1..0..0....0..1..1....0..0..1....0..1..1....1..0..1....0..1..0

CROSSREFS

Sequence in context: A214403 A261527 A292436 * A205399 A135303 A036065

Adjacent sequences:  A184094 A184095 A184096 * A184098 A184099 A184100

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Jan 09 2011

STATUS

approved

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Last modified September 19 05:33 EDT 2020. Contains 337176 sequences. (Running on oeis4.)