A189955 1/4 the number of arrangements of 6 nonzero numbers x(i) in -n..n with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero

16, 280, 2393, 9884, 31284, 77459, 168737, 327880, 595697, 1005710, 1621554, 2504978, 3738572, 5418036, 7662698, 10565406, 14315713, 19055943, 24956731, 32281835, 41217268, 51991454, 64917759, 80355606, 98539718, 119899372

Offset

1,1

Comments

Row 5 of A189951

Links

R. H. Hardin, Table of n, a(n) for n = 1..125

Example

Some solutions with n=3
..3...-1...-3...-3....3....2...-2...-1...-2...-2....3...-2....1....3...-1....1
.-2....2...-1....2...-2....1....1....3....3...-2...-2....1...-1....2...-3...-1
.-2....1....3....1...-1....2...-2...-3...-1...-1...-3...-3....1...-1....2...-1
..3...-2...-2...-2...-2...-1...-3....3....1...-1...-3...-3...-1...-1....2....3
..2....2...-2...-2....2...-2....1....2....3....3....1...-1....1...-3....2....3
..2....1....2...-1....2....1....2...-1....2...-2...-2...-2...-1...-3....3....2

Crossrefs

Sequence in context: A363754 A004382 A204955 * A038758 A240336 A281341

Adjacent sequences: A189952 A189953 A189954 * A189956 A189957 A189958

Keyword

nonn

Author

R. H. Hardin May 02 2011

Status

approved