Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 4 times.
A248838
Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 4 times.
Terms
- a(0) =2a(1) =6a(2) =24a(3) =120a(4) =718a(5) =4994a(6) =39556a(7) =351320a(8) =3456742a(9) =37314126a(10) =438366374a(11) =5567209930a(12) =75995663398
External references
- oeis: A248838