Number of permutations of 4 copies of 1..n introduced in order 1..n with no element equal to another within a distance of 2.
A190831
Number of permutations of 4 copies of 1..n introduced in order 1..n with no element equal to another within a distance of 2.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =1277a(4) =1903102a(5) =4336589521
External references
- oeis: A190831