A194022 Number of ways to arrange 8 points on an n X n X n triangular grid on an isosceles triangle so that it balances at the midpoint of its central altitude.

0, 0, 0, 0, 21, 560, 6425, 47385, 262382, 1180469, 4530030, 15317274, 46696163, 130554918, 339126948, 826821895, 1907572610, 4192279515, 8824669582, 17873749440, 34969097933, 66304228516, 122186400487, 219382723103

Offset

1,5

Comments

Column 8 of A194024.

Links

R. H. Hardin, Table of n, a(n) for n = 1..31

Example

Some solutions for 5 X 5 X 5:
......1..........1..........1..........1..........1..........1..........1
.....1.1........1.1........1.1........1.1........1.1........1.0........1.1
....0.1.1......1.1.0......1.1.0......0.1.1......1.0.1......1.1.1......0.1.1
...1.0.0.1....0.0.1.1....1.0.0.1....0.1.1.0....1.0.1.0....1.0.1.1....0.1.0.1
..0.1.0.0.0..0.1.0.0.0..0.0.0.1.0..0.1.0.0.0..0.0.0.1.0..0.0.0.0.0..1.0.0.0.0

Crossrefs

Sequence in context: A034789 A297635 A292062 * A183730 A341572 A199254

Adjacent sequences: A194019 A194020 A194021 * A194023 A194024 A194025

Keyword

nonn

Author

R. H. Hardin, Aug 12 2011

Status

approved