Number of (n+1)X(1+1) 0..1 arrays with every element equal to some horizontal, vertical, diagonal or antidiagonal neighbor, with top left element zero.
A231950
Number of (n+1)X(1+1) 0..1 arrays with every element equal to some horizontal, vertical, diagonal or antidiagonal neighbor, with top left element zero.
Terms
- a(0) =4a(1) =18a(2) =64a(3) =236a(4) =888a(5) =3336a(6) =12512a(7) =46928a(8) =176032a(9) =660320a(10) =2476928a(11) =9291200a(12) =34852224a(13) =130734208a(14) =490397184a(15) =1839529216a(16) =6900259328a(17) =25883567616a(18) =97091868672a(19) =364201376768
External references
- oeis: A231950