12338740736domain: NAppears in sequencesNumber of permutations p of {1..2n} such that p[2k-1]<p[2k] <=> p[2k]<p[2k+1].at n=7A261683Array read by antidiagonals: T(m,n) (m>=1, n>=1) = number of m X n whirlpool permutations.at n=37A334518