A220546 Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.
1, 8, 224, 32173, 21668208, 69961268156, 1077372801893440, 79222784184855853978, 27809964251933826835780981, 46605836505704256743057461864323
Offset: 1
Keywords
Examples
Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10) ..0..8..8....0..0..8....6..4..7....8..0..0....6..4..0....8..6..4....0..0..7 ..8..2..2....0..7..2....8..3..0....2..8..8....0..7..0....2..8..0....0..3..0 ..2..0..0....3..0..0....2..0..0....0..2..2....3..6..4....0..2..0....0..6..4
Links
- R. H. Hardin, Table of n, a(n) for n = 1..12
Comments