A250163 Number of length n+1 0..4 arrays with the sum of adjacent differences multiplied by some arrangement of +-1 equal to zero.

5, 33, 211, 1269, 7109, 37881, 195927, 996933, 5029417, 25262121, 126608171, 633821781, 3171197325, 15861685497, 79324281727, 396666275397, 1983460173617, 9917674841193, 49589469690579, 247950578857365, 1239762467069077

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..55

Formula

Empirical: a(n) = 16*a(n-1) -105*a(n-2) +372*a(n-3) -783*a(n-4) +1008*a(n-5) -779*a(n-6) +332*a(n-7) -60*a(n-8).

Empirical g.f.: x*(5 - 47*x + 208*x^2 - 502*x^3 + 599*x^4 - 311*x^5 + 52*x^6 + 44*x^7) / ((1 - x)^4*(1 - 2*x)^2*(1 - 3*x)*(1 - 5*x)). - Colin Barker, Nov 12 2018

Example

Some solutions for n=6:
..3....0....1....0....1....2....0....4....4....4....1....3....4....1....1....0
..2....1....0....0....2....3....4....1....4....3....1....0....2....3....3....4
..3....1....4....2....3....2....0....0....1....0....3....2....4....4....0....3
..2....2....2....1....3....0....0....0....0....0....4....4....1....2....4....0
..0....0....4....3....1....4....3....1....4....2....4....1....3....4....3....1
..2....0....2....1....3....0....1....2....2....2....3....2....2....3....2....2
..3....2....3....0....3....0....2....2....4....0....1....3....0....3....1....2

Crossrefs

Column 4 of A250167.

Sequence in context: A197675 A015544 A155597 * A164538 A197533 A221441

Adjacent sequences: A250160 A250161 A250162 * A250164 A250165 A250166

Keyword

nonn

Author

R. H. Hardin, Nov 13 2014

Status

approved