Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 2Xn array.
A220936
Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 2Xn array.
Terms
- a(0) =1a(1) =4a(2) =16a(3) =52a(4) =200a(5) =792a(6) =3080a(7) =12164a(8) =47827a(9) =188078a(10) =739654a(11) =2908308a(12) =11433623a(13) =44951623a(14) =176719636a(15) =694738324a(16) =2731215010a(17) =10737125607a(18) =42210368413a(19) =165939449883a(20) =652348443363
External references
- oeis: A220936