A188354 Number of arrangements of n+1 numbers x(i) in -5..5 with the sum of x(i)*x(i+1) equal to zero

21, 231, 749, 8051, 45801, 480363, 3882729, 40629247, 383541193, 4033546763, 40584302909, 428984471067, 4442125791917, 47152504083651, 495572482473621, 5279048333736159, 55969066137457201, 598015958507349743

Offset

1,1

Comments

Column 5 of A188358

Links

R. H. Hardin, Table of n, a(n) for n = 1..39

Example

Some solutions for n=4
..1...-4...-5...-4....3....5....5....1...-5...-4....0...-5...-1....5...-3....1
..0...-4....3...-5....5...-1...-4...-2...-3...-4....0....0....0....2....2....4
..2...-3....3....3...-3....4....3...-4....1....4....4....3....0...-5....5....5
.-2....4....2...-1....5....3....4....2...-4....0....0...-1....0....4...-2...-3
.-2...-4....0....2....3...-1....5....1....2...-2...-5...-3....2....5...-3....3

Crossrefs

Sequence in context: A220721 A320588 A020267 * A064322 A126902 A162646

Adjacent sequences: A188351 A188352 A188353 * A188355 A188356 A188357

Keyword

nonn

Author

R. H. Hardin Mar 28 2011

Status

approved