A226394 Number of nondecreasing -3..3 vectors of length n whose dot product with some nonincreasing -3..3 vector equals n

2, 20, 68, 146, 258, 756, 1012, 1866, 3762, 5020, 6854, 13706, 15514, 22540, 38982, 43620, 54834, 96164, 98406, 128232, 207814, 213600, 253828, 414128, 402352, 495006, 764912, 744280, 859550, 1342098, 1253162, 1483672, 2231178, 2095910

Offset

1,1

Comments

Column 3 of A226398

Links

R. H. Hardin, Table of n, a(n) for n = 1..41

Example

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

Crossrefs

Sequence in context: A230644 A183907 A216609 * A287485 A003283 A259110

Adjacent sequences: A226391 A226392 A226393 * A226395 A226396 A226397

Keyword

nonn

Author

R. H. Hardin Jun 06 2013

Status

approved