A194014 Number of ways to arrange 9 points on an n X n X n triangular grid so that it balances at its center.

0, 0, 0, 1, 136, 4130, 62514, 604546, 4291625, 24185859, 113919241, 464544503, 1682475175, 5516378285, 16616546191, 46520940879, 122188233722, 303383298778, 716597693883, 1618737603962, 3512685981565, 7350652764391, 14882247432591

Offset

1,5

Comments

Column 9 of A194016.

Links

R. H. Hardin, Table of n, a(n) for n = 1..35

Example

Some solutions for 7 X 7 X 7:
........0..............1..............0..............1..............1
.......0.1............1.0............0.1............1.0............0.0
......0.1.0..........0.0.0..........1.1.0..........0.0.0..........1.0.0
.....0.1.0.1........0.0.1.0........0.0.0.0........0.0.0.0........0.0.0.1
....1.0.0.0.0......0.0.0.1.0......1.0.0.0.0......0.1.1.0.0......0.0.0.0.1
...0.0.0.0.0.1....1.0.0.0.0.1....0.1.0.1.1.0....0.1.0.0.1.1....1.1.0.0.0.1
..0.1.1.0.1.0.0..0.1.0.1.1.0.0..0.0.0.1.0.1.0..1.0.0.0.0.1.0..0.0.1.1.0.0.0

Crossrefs

Sequence in context: A071231 A233102 A249237 * A248452 A035819 A233086

Adjacent sequences: A194011 A194012 A194013 * A194015 A194016 A194017

Keyword

nonn

Author

R. H. Hardin, Aug 11 2011

Status

approved