A190072 Number of arrangements of 3 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.

4, 12, 36, 76, 143, 233, 366, 536, 760, 1028, 1363, 1751, 2221, 2758, 3387, 4096, 4907, 5804, 6819, 7931, 9174, 10525, 12021, 13631, 15401, 17299, 19366, 21572, 23959, 26490, 29220, 32114, 35210, 38476, 41963, 45629, 49527, 53618, 57953, 62489, 67285

Offset

1,1

Comments

Row 2 of A190071.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Example

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

Crossrefs

Cf. A190071.

Sequence in context: A020875 A307182 A357061 * A063810 A183931 A320967

Adjacent sequences: A190069 A190070 A190071 * A190073 A190074 A190075

Keyword

nonn

Author

R. H. Hardin, May 04 2011

Status

approved