A202001 Number of -3..3 circular arrays x(0..n+1) of n+2 elements with zero sums of x(i) and x(i)*x((i+1) mod (n+2))

1, 49, 61, 601, 2605, 22865, 101395, 657871, 3603821, 25726609, 150646627, 1027976993, 6463089721, 43715824593, 278513680357, 1863303355141, 12132105992613, 81455933000439, 537677650826359, 3614341859258835

Offset

1,2

Comments

Column 3 of A202006

Links

R. H. Hardin, Table of n, a(n) for n = 1..74

Example

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

Crossrefs

Sequence in context: A111327 A184033 A178951 * A038640 A326151 A216165

Adjacent sequences: A201998 A201999 A202000 * A202002 A202003 A202004

Keyword

nonn

Author

R. H. Hardin Dec 07 2011

Status

approved