A192499 Half the number of nXnXn triangular binary arrays with every element unequal to at most 3 neighbors

1, 4, 26, 196, 2092, 28686, 534806, 13182070, 433981798, 19015675154, 1110527815484, 86390598478646, 8953005948663932, 1236137340970342866, 227372493923183802446

Offset

1,2

Links

Table of n, a(n) for n=1..15.

Example

Some solutions for 5X5X5 with a(1,1)=0
......0..........0..........0..........0..........0..........0..........0
.....1.1........0.0........1.1........0.0........1.1........0.1........1.0
....1.1.0......1.1.0......1.1.1......1.0.1......0.0.0......1.0.1......1.1.1
...0.0.0.0....1.1.1.0....0.1.1.1....1.0.0.1....0.0.0.1....1.0.0.0....0.0.1.0
..0.0.0.0.1..0.0.1.1.1..0.0.0.0.0..0.0.0.1.0..0.1.1.1.0..1.0.0.0.0..0.0.0.1.0

Crossrefs

Sequence in context: A198024 A278393 A349361 * A376320 A271935 A246509

Adjacent sequences: A192496 A192497 A192498 * A192500 A192501 A192502

Keyword

nonn

Author

R. H. Hardin Jul 02 2011

Status

approved