Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly two horizontal and vertical neighbors, without consecutive collinear links.
A220613
Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly two horizontal and vertical neighbors, without consecutive collinear links.
Terms
- a(0) =1a(1) =21a(2) =85a(3) =781a(4) =4673a(5) =34981a(6) =233265a(7) =1653229a(8) =11354857a(9) =79290645a(10) =548972737a(11) =3817993565a(12) =26491584361a(13) =184040357765
External references
- oeis: A220613