A202078 Number of arrays of 7 integers in -n..n with sum zero and the sum of every adjacent pair being odd

6, 96, 1014, 3752, 15010, 35604, 95342, 181834, 390544, 654086, 1221708, 1876930, 3183404, 4598874, 7268148, 10026924, 15014418, 19984692, 28678218, 37094052, 51428190, 64980344, 87564274, 108501126, 142759916, 173998474, 224327824

Offset

1,1

Comments

Row 5 of A202076

Links

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

Formula

Empirical: a(n) = a(n-1) +6*a(n-2) -6*a(n-3) -15*a(n-4) +15*a(n-5) +20*a(n-6) -20*a(n-7) -15*a(n-8) +15*a(n-9) +6*a(n-10) -6*a(n-11) -a(n-12) +a(n-13)

Example

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

Crossrefs

Sequence in context: A030989 A288845 A006044 * A227262 A001805 A139743

Adjacent sequences: A202075 A202076 A202077 * A202079 A202080 A202081

Keyword

nonn

Author

R. H. Hardin Dec 10 2011

Status

approved