A188249 T(n,k)=Number of arrangements of n+2 nonzero numbers x(i) in -k..k with the sum of x(i)*x(i+1) equal to zero

4, 16, 0, 36, 20, 12, 64, 52, 120, 0, 100, 144, 548, 300, 40, 144, 208, 1504, 1632, 1284, 0, 196, 436, 3292, 7092, 12692, 4132, 140, 256, 532, 6376, 16484, 58824, 51196, 16272, 0, 324, 816, 10564, 43440, 193232, 368588, 355396, 57808, 504, 400, 1072, 17040, 75080

Offset

1,1

Comments

Table starts

...4.....16.......36.........64.........100.........144..........196

...0.....20.......52........144.........208.........436..........532

..12....120......548.......1504........3292........6376........10564

...0....300.....1632.......7092.......16484.......43440........75080

..40...1284....12692......58824......193232......521124......1142180

...0...4132....51196.....368588.....1399640.....4875112.....11953848

.140..16272...355396....2880240....14715004....55994544....168083116

...0..57808..1657632...20265640...123729664...591604824...2026547348

.504.223308.10858368..156028036..1247614580..6764014136..27843005992

...0.828456.54754656.1154193268.11199296500.75116513672.355600251460

Links

R. H. Hardin, Table of n, a(n) for n = 1..159

Example

Some solutions for n=6 k=4
.-2...-3...-3...-1...-2...-1....1....2...-3...-4....3...-4...-2...-4...-4...-2
.-2...-4...-4...-4...-4...-4...-4...-4...-2...-3...-4...-3...-3...-4...-3...-4
.-3...-2...-2....4....3....2....1....1...-4....3...-2....1....3....2....1....2
.-4...-2...-1...-1....1...-1....2...-4....2...-4....1...-3...-1....2....4....4
..3....4...-4...-4...-2...-2...-1...-2...-2...-3....1....1...-2...-1....2...-3
.-2...-4....2...-3....1...-2...-2...-3....4....3....4...-3...-3....1...-3...-4
..1...-3...-3...-3....1...-2...-1....2....3....3....1....3...-2....3....3....4
.-2....4....4....3....4....2...-4....4...-2...-1...-3....3....4...-4...-2....2

Crossrefs

Column 1 is 4*A138364

Sequence in context: A061849 A052107 A069019 * A228559 A165410 A016486

Adjacent sequences: A188246 A188247 A188248 * A188250 A188251 A188252

Keyword

nonn,tabl

Author

R. H. Hardin Mar 25 2011

Status

approved