Number of ways to reciprocally link elements of an n X 5 array either to themselves or to exactly two horizontal and vertical neighbors, without consecutive collinear links.

A220611

Number of ways to reciprocally link elements of an n X 5 array either to themselves or to exactly two horizontal and vertical neighbors, without consecutive collinear links.

Terms

    a(0) =1a(1) =8a(2) =21a(3) =95a(4) =324a(5) =1277a(6) =4673a(7) =17768a(8) =66245a(9) =249499a(10) =934816a(11) =3511945a(12) =13175625a(13) =49465544a(14) =185641901a(15) =696836263a(16) =2615432756a(17) =9816980965a(18) =36846924297a(19) =138302568456a(20) =519106314333

External references