A320365 Number of n X n 0..1 arrays with every element unequal to 0, 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 8, 228, 19840, 5304988, 4358279956, 10993944343316, 85188280351091996, 2027436931101188931860, 148202875581543610186349592

Offset

1,2

Comments

Diagonal of A320371.

Links

Table of n, a(n) for n=1..10.

Example

Some solutions for n=5:
  0 0 0 0 0    0 0 0 0 0    0 0 0 0 0    0 0 0 0 0
  0 0 0 1 1    0 0 0 0 0    0 1 1 0 1    0 1 1 0 0
  0 1 1 0 0    0 1 1 1 1    0 1 1 0 1    1 1 1 0 0
  0 1 1 0 0    0 1 0 1 0    1 0 0 1 0    0 0 0 0 0
  1 0 0 1 0    0 0 0 0 0    0 1 0 1 0    0 1 0 0 0

Crossrefs

Cf. A320371.

Sequence in context: A316809 A299655 A033508 * A317559 A302735 A300209

Adjacent sequences: A320362 A320363 A320364 * A320366 A320367 A320368

Keyword

nonn,more

Author

R. H. Hardin, Oct 11 2018

Status

approved