A193483 Number of n X n symmetric 0..4 arrays with each element equal to the product mod 5 of two of its horizontal and vertical neighbors

0, 2, 20, 855, 107162, 54992415, 87587532068, 474408802145495

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for 4X4
..1..1..1..3....0..0..2..2....1..4..3..4....4..3..2..4....1..1..2..2
..1..4..2..3....0..1..1..1....4..4..2..3....3..0..0..2....1..3..3..1
..1..2..4..4....2..1..1..1....3..2..1..1....2..0..4..3....2..3..0..0
..3..3..4..1....2..1..1..1....4..3..1..1....4..2..3..4....2..1..0..0

Crossrefs

Sequence in context: A333464 A356691 A163594 * A013148 A276892 A006547

Adjacent sequences: A193480 A193481 A193482 * A193484 A193485 A193486

Keyword

nonn

Author

R. H. Hardin Jul 27 2011

Status

approved