A188253
Number of arrangements of 7 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.
Original entry on oeis.org
40, 1284, 12692, 58824, 193232, 521124, 1142180, 2347608, 4323448, 7567844, 12129300, 19691552, 29057776, 42900188, 61593740, 86648240
Offset: 1
Some solutions for n=4
..1....2...-3...-1...-1....1...-1....4...-1....4...-1....4...-1....2....4....3
.-2....1....3....3...-2....1....3...-1....1....3....2....4...-3....3...-3...-2
..4....4....4....3...-2....2....1...-4...-3...-3...-1....2...-3...-1...-4....1
..2...-4...-4...-4...-2....3....2....3...-1....1....1...-2....4...-1...-1....4
.-3...-4...-4...-1....1...-2...-3....3....2....1....4....4....4...-2....4....2
.-4....3....3....2...-4....1...-4....3....1....1....1...-2...-2...-3...-3....4
..1....2....3....2....1...-1....2...-2....1...-2...-3....2....4....4...-4...-3
A188254
Number of arrangements of 8 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.
Original entry on oeis.org
0, 4132, 51196, 368588, 1399640, 4875112, 11953848, 28779900, 58731504, 116157280, 200181920, 362242468, 569517636
Offset: 1
Some solutions for n=4
.-4...-1....1...-4....3...-2...-2...-2...-4....1....1...-3....4...-4...-2....2
.-2...-4...-3...-3...-4...-4...-2...-3...-2...-3...-4...-2...-4...-4...-4...-3
..4...-2...-3....2...-4...-1....3....1....3...-2....3...-2....1....4...-4....3
..3....2....1...-1....3...-3...-2...-3....2....2....4....1....3...-2...-4...-3
.-3...-1....3...-2....3....3...-4...-3...-1...-2...-1...-2....3...-2....3...-3
..1....1...-2....4...-1...-2....3....2...-2...-1....2....4....3...-2...-4...-1
.-3...-1...-4....1....2...-2....2....3...-4....3....2....1....1....3....2...-3
.-1....4....2...-2....2....2....3...-3....4....2....3...-2...-4....2...-4...-3
A188255
Number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.
Original entry on oeis.org
140, 16272, 355396, 2880240, 14715004, 55994544, 168083116, 445304272, 1033172284, 2215496776, 4323822892
Offset: 1
Some solutions for n=4
.-4...-2...-3...-4...-3...-3...-4...-3...-4...-3...-3...-3...-2...-2...-4...-4
.-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4
.-2....1....3....1....1....1....1....1....1...-3....4....2...-4...-3...-2....3
.-1....1...-4....2...-1....3...-4...-1...-2....2....1....2...-4...-4....3....4
.-4...-3...-3...-1...-1...-1....4....3...-1...-2....3...-1....3....2...-1...-1
..3....4...-3....3...-2....4....2...-4....1....1...-2...-3...-1...-3...-2....4
.-1....3....1...-2....3...-1....3...-2....3...-4...-1....2....4....4....4....2
..3....2....2....3...-1...-4...-3....1...-2....4....1...-3...-3...-1...-3...-4
.-4...-4...-4....1....1....1...-1....2....4....2....2...-1....3....2...-1....2
A188256
Number of arrangements of 10 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.
Original entry on oeis.org
0, 57808, 1657632, 20265640, 123729664, 591604824, 2026547348, 6250275112, 16132348896, 38938013924
Offset: 1
Some solutions for n=4
.-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4
.-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4...-4
..1....1...-2...-1...-1....1...-2...-2...-2....1....1....1...-1...-1....1...-2
.-1...-4....1...-4...-4....2....4....4....2...-1...-3...-3....3...-4...-4...-2
.-1...-4...-4....4...-3...-1....3...-3...-2...-2...-2...-3...-3....2....4....4
..1...-3....2...-3....3...-4...-4....2....2...-3...-1...-1....2....4...-1...-3
.-1....4....1...-4...-1....4...-1...-3...-3....1...-1....3...-4...-3...-4....1
.-2...-3....3....2....4....1...-4...-4....4...-4....2....2...-2...-3...-3...-2
..3....2...-3....3...-4...-2....4....2....3....2...-4...-4....2....3...-4....3
.-2...-3....2...-2....1....1...-2....2...-2...-2....2....4....1...-4....4....1
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