A250555 Number of length n+2 0..2 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero

5, 25, 83, 297, 989, 3113, 9611, 29257, 88503, 266769, 802699, 2412545, 7246311, 21755889, 65301163, 195969945, 588042095, 1764390025, 5293696363, 15882140601, 47648522543, 142949767457, 428857697715, 1286589881041, 3859803210479

Offset

1,1

Comments

Column 2 of A250561

Links

R. H. Hardin, Table of n, a(n) for n = 1..106

Formula

Empirical: a(n) = 4*a(n-1) +2*a(n-2) -17*a(n-3) -3*a(n-4) +24*a(n-5) +16*a(n-6) -13*a(n-7) -26*a(n-8) +2*a(n-9) +12*a(n-10) for n>15

Example

Some solutions for n=6
..2....1....2....0....0....2....0....2....0....2....2....2....1....2....1....0
..1....0....2....2....0....0....2....2....0....2....0....1....0....2....1....0
..2....1....2....1....1....2....2....1....0....0....2....0....1....1....1....2
..1....0....0....0....2....2....0....2....2....2....0....0....0....0....2....2
..1....0....0....0....1....1....0....0....1....1....1....0....0....1....2....0
..1....0....0....0....0....2....0....1....1....2....1....2....1....0....1....2
..2....1....0....1....1....1....2....1....2....2....0....0....1....0....0....2
..1....2....0....1....1....1....0....1....2....0....0....1....0....2....2....2

Crossrefs

Sequence in context: A147114 A296669 A131537 * A147122 A051229 A058919

Adjacent sequences: A250552 A250553 A250554 * A250556 A250557 A250558

Keyword

nonn

Author

R. H. Hardin, Nov 25 2014

Status

approved