2340480

Appears in sequences

• Number of permutations p of {1..2n} such that p[2k-1]<p[2k] <=> p[2k]<p[2k+1].at n=5A261683
• Array read by antidiagonals: T(m,n) (m>=1, n>=1) = number of m X n whirlpool permutations.at n=22A334518
• Array read by antidiagonals: T(m,n) (m>=1, n>=1) = number of m X n whirlpool permutations.at n=26A334518
• Triangle read by rows: T(n,k) (1<=k<=n) = number of n X k whirlpool permutations (see A334518).at n=16A334519