Number of nX4 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
A281559
Number of nX4 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
Terms
- a(0) =0a(1) =18a(2) =621a(3) =3374a(4) =15508a(5) =53568a(6) =162919a(7) =463916a(8) =1262057a(9) =3344312a(10) =8682013a(11) =22096236a(12) =55418093a(13) =137452378a(14) =337368553a(15) =820589074a(16) =1981158104a(17) =4751265748a(18) =11325996647a(19) =26856461774a(20) =63380869317a(21) =148929846348a(22) =348578197271
External references
- oeis: A281559