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

Author

R. H. Hardin Mar 25 2011

Keywords

• nonn
• tabl

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

Examples

			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
		

Links

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

Crossrefs

Column 1 is 4*A138364