Number of ways to reciprocally link elements of an 4Xn array either to themselves or to exactly one horizontal or antidiagonal neighbor.

A220565

Number of ways to reciprocally link elements of an 4Xn array either to themselves or to exactly one horizontal or antidiagonal neighbor.

Terms

    a(0) =1a(1) =34a(2) =292a(3) =3966a(4) =45966a(5) =561636a(6) =6743873a(7) =81437539a(8) =981628768a(9) =11839220919a(10) =142763980945

External references