A200457 Number of -n..n arrays x(0..4) of 5 elements with zero sum and nonzero first and second differences

6, 144, 728, 2334, 5720, 12002, 22276, 38174, 61290, 93704, 137374, 194964, 268842, 362092, 477620, 618954, 789324, 992970, 1233412, 1515270, 1842742, 2220844, 2654034, 3148080, 3707758, 4339192, 5047836, 5840186, 6721964, 7700510, 8781768

Offset

1,1

Comments

Row 3 of A200454

Links

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

Formula

Empirical: a(n) = -a(n-1) +a(n-3) +2*a(n-4) +2*a(n-5) +a(n-6) -a(n-8) -a(n-9) -a(n-10) -2*a(n-11) -2*a(n-12) -2*a(n-13) -a(n-14) +a(n-15) +2*a(n-16) +2*a(n-17) +2*a(n-18) +a(n-19) +a(n-20) +a(n-21) -a(n-23) -2*a(n-24) -2*a(n-25) -a(n-26) +a(n-28) +a(n-29)

Example

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

Crossrefs

Sequence in context: A349076 A037049 A196811 * A128785 A197178 A208230

Adjacent sequences: A200454 A200455 A200456 * A200458 A200459 A200460

Keyword

nonn

Author

R. H. Hardin Nov 18 2011

Status

approved