A193809 Number of n X n symmetric 0..4 arrays with no element equal to the difference mod 5 of any two of its horizontal and vertical neighbors

5, 52, 496, 7536, 224792, 13949968, 1780090736, 465161983824, 246624000644912, 263286800959827832, 563752320057171922352, 2417354884909931307656688, 20747077497647444504550311672

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Example

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

Crossrefs

Sequence in context: A081075 A247766 A247777 * A134111 A071583 A099881

Adjacent sequences: A193806 A193807 A193808 * A193810 A193811 A193812

Keyword

nonn

Author

R. H. Hardin Aug 05 2011

Status

approved