2265024
domain: N
Appears in sequences
- Number of permutations of the multiset {1,1,1,1,2,2,2,2,3,3,3,3,...,n,n,n,n} with no two consecutive terms equal.at n=4A321633
- Number of arrangements of n 1's, n 2's, ..., n n's avoiding equal consecutive terms.at n=4A321634
- Square array A(n,k), n >= 1, k >= 1, read by antidiagonals, where A(n,k) is the number of permutations of n copies of 1..k with no element equal to another within a distance of 1.at n=24A322093
- a(1) = 2, a(n) = k - 1, where k is the least number greater than a(n-1) such that rad(k) | a(n-1), where rad(n) = A007947(n).at n=31A365413