Number of nX1 0..3 arrays with values 0..3 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.
A199194
Number of nX1 0..3 arrays with values 0..3 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) =1a(2) =1a(3) =1a(4) =6a(5) =21a(6) =41a(7) =36a(8) =281a(9) =1051a(10) =2056a(11) =1721a(12) =15131a(13) =58951a(14) =115631a(15) =94376a(16) =887643a(17) =3551235a(18) =6981925a(19) =5609649a(20) =55101276a(21) =224543335a(22) =442311619a(23) =351574834a(24) =3559509379a(25) =14702228029a(26) =29006278734a(27) =22875971289a(28) =236833911819
External references
- oeis: A199194