Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..2 2Xn array.
A220795
Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..2 2Xn array.
Terms
- a(0) =1a(1) =6a(2) =19a(3) =76a(4) =267a(5) =1074a(6) =4069a(7) =15916a(8) =62161a(9) =243418a(10) =954189a(11) =3745072a(12) =14698115a(13) =57707746a(14) =226582983a(15) =889710492a(16) =3493659533a(17) =13718948094a(18) =53871964175a(19) =211547211964a(20) =830715606031
External references
- oeis: A220795