Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 3 times.
A248837
Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 3 times.
Terms
- a(0) =2a(1) =6a(2) =24a(3) =118a(4) =686a(5) =4598a(6) =34872a(7) =295044a(8) =2753958a(9) =28103804a(10) =311216626a(11) =3716341042a(12) =47597786154a(13) =650812077852
External references
- oeis: A248837