A202002 Number of -4..4 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, 81, 101, 1357, 7463, 80065, 490879, 3697331, 28156261, 240962805, 1907124597, 16026836953, 133898693111, 1130246507329, 9448228560881, 79776887571979, 675881669398761, 5767799951404371, 49328839761741989, 423380827767076411

Offset

1,2

Comments

Column 4 of A202006

Links

R. H. Hardin, Table of n, a(n) for n = 1..53

Example

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

Crossrefs

Sequence in context: A104113 A102766 A256349 * A249613 A064828 A265135

Adjacent sequences: A201999 A202000 A202001 * A202003 A202004 A202005

Keyword

nonn

Author

R. H. Hardin Dec 07 2011

Status

approved