Number of permutations of n copies of 1..7 introduced in order 1..7 with no element equal to another within a distance of 2.
A190928
Number of permutations of n copies of 1..7 introduced in order 1..7 with no element equal to another within a distance of 2.
Terms
- a(0) =1a(1) =15422a(2) =418539642
External references
- oeis: A190928