A188358 T(n,k)=Number of arrangements of n+1 numbers x(i) in -k..k with the sum of x(i)*x(i+1) equal to zero

5, 9, 15, 13, 45, 29, 17, 91, 117, 91, 21, 153, 257, 565, 197, 25, 231, 497, 1775, 1953, 627, 29, 325, 749, 4201, 7369, 9153, 1477, 33, 435, 1205, 8051, 22229, 49747, 37269, 4671, 37, 561, 1569, 14477, 45801, 181449, 262925, 173409, 11693, 41, 703, 2161

Offset

1,1

Comments

Table starts

.....5.......9.......13........17.........21..........25..........29

....15......45.......91.......153........231.........325.........435

....29.....117......257.......497........749........1205........1569

....91.....565.....1775......4201.......8051.......14477.......22583

...197....1953.....7369.....22229......45801......100885......163745

...627....9153....49747....181449.....480363.....1171345.....2295051

..1477...37269...262925...1264985....3882729....11535493....25217201

..4671..173409..1763151..10396729...40629247...136061137...355442823

.11693..766869.10536621..81850801..383541193..1540834589..4602176797

.36487.3589357.70819767.684867741.4033546763.18592832393.65556183495

Links

R. H. Hardin, Table of n, a(n) for n = 1..178

Example

Some solutions for n=6 k=4
.-4...-1...-4....0....3....0...-1....0...-4...-1...-1...-1...-2...-1....1...-3
..0...-2...-3...-2...-4...-4...-3...-4....0...-1...-2...-3...-2....0...-2...-1
.-4....2....3....1....3....4...-3...-1....4....0....1....1...-2....4....1....1
..4...-1...-1....1....3....4....0...-2....0....0...-3...-4....1...-4...-4....2
..4....2....2....1....1....0....1....3...-2...-3...-1...-1...-2...-4....3...-3
..3....1...-2....0...-4....1...-3...-2....0...-1....0....2....1...-4....4...-1
.-4....4...-3...-1...-4....0....3...-3...-4....4....3....1...-2....4....2....1

Crossrefs

Row 1 is A016813

Row 2 is A014634

Sequence in context: A107980 A163161 A331556 * A228218 A361993 A314993

Adjacent sequences: A188355 A188356 A188357 * A188359 A188360 A188361

Keyword

nonn,tabl

Author

R. H. Hardin Mar 28 2011

Status

approved