A220704 Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly two horizontal and antidiagonal neighbors, without consecutive collinear links.

1, 1, 3, 13, 107, 1617, 44976, 2282408, 216083336, 37166744488, 11934907610044, 6974153590170208, 7595477025017870022, 15083748097547577433271, 55729708477784939752304144, 376141278066033748724918163244

Offset: 1

Author

R. H. Hardin Dec 18 2012

Keywords

• nonn

Comments

Diagonal of A220708

Examples

			All solutions for n=3 0=self 3=ne 4=w 6=e 7=sw (reciprocal directions total 10)
.00.00.00...00.67.47...00.00.00
.00.00.00...36.34.00...00.67.47
.00.00.00...00.00.00...36.34.00
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..18