Number of nX5 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.
A301820
Number of nX5 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.
Terms
- a(0) =3a(1) =18a(2) =74a(3) =299a(4) =1197a(5) =4785a(6) =19130a(7) =76499a(8) =305959a(9) =1223777a(10) =4895020a(11) =19579955a(12) =78319649a(13) =313278369a(14) =1253113182a(15) =5012452355a(16) =20049808955a(17) =80199235249a(18) =320796940304
External references
- oeis: A301820