70673825domain: NAppears in sequencesColumn 1 of triangle A128564; a(n) equals the number of permutations of {1..n+2} with [n/2+1] inversions for n>=0.at n=20A128565Number of reduced words of length n in the Weyl group A_21.at n=11A161518Number of permutations of [2n] with n inversions.at n=11A384368