Number of ways to reciprocally link elements of an n X 3 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.
A220597
Number of ways to reciprocally link elements of an n X 3 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.
Terms
- a(0) =1a(1) =7a(2) =65a(3) =471a(4) =3469a(5) =25747a(6) =190425a(7) =1408823a(8) =10424813a(9) =77135267a(10) =570740149a(11) =4223043591a(12) =31247282909a(13) =231205914319
External references
- oeis: A220597