A202079 Number of arrays of 8 integers in -n..n with sum zero and the sum of every adjacent pair being odd.

12, 524, 5832, 34632, 142692, 462436, 1264272, 3044496, 6644604, 13406844, 25370840, 45516120, 78055380, 128783316, 205485856, 318414624, 480831468, 709627884, 1026024168, 1456353128, 2032933188, 2795035716, 3789951408

Offset

1,1

Comments

Row 6 of A202076.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-1) -28*a(n-2) +56*a(n-3) -70*a(n-4) +56*a(n-5) -28*a(n-6) +8*a(n-7) -a(n-8).

Empirical g.f.: 4*x*(1 + x)*(3 + 104*x + 390*x^2 + 104*x^3 + 3*x^4) / (1 - x)^8. - Colin Barker, May 27 2018

Example

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

Crossrefs

Cf. A202076.

Sequence in context: A198056 A360644 A004801 * A296685 A281030 A282589

Adjacent sequences: A202076 A202077 A202078 * A202080 A202081 A202082

Keyword

nonn

Author

R. H. Hardin, Dec 10 2011

Status

approved