Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.
A199240
Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =12a(4) =36a(5) =39a(6) =288a(7) =836a(8) =888a(9) =7380a(10) =22149a(11) =23706a(12) =201515a(13) =611372a(14) =654468a(15) =5704006a(16) =17499974a(17) =18760333a(18) =166063522a(19) =513160156a(20) =550594928a(21) =4932198432a(22) =15327377362a(23) =16456851660a(24) =148765279666a(25) =464332349724a(26) =498808175988
External references
- oeis: A199240