Number of ways to reciprocally link elements of an n X 5 array either to themselves or to exactly two horizontal or antidiagonal neighbors.

A220629

Number of ways to reciprocally link elements of an n X 5 array either to themselves or to exactly two horizontal or antidiagonal neighbors.

Terms

    a(0) =1a(1) =8a(2) =44a(3) =257a(4) =1481a(5) =8560a(6) =49448a(7) =285669a(8) =1650333a(9) =9534128a(10) =55079528a(11) =318199485a(12) =1838267585a(13) =10619840324a(14) =61351790884a(15) =354434918989

External references