588833domain: NAppears in sequencesNumber of reduced words of length n in the Weyl group E_8 on 8 generators and order 696729600.at n=22A162494a(0) = 1 and a(n) = (1/n) * Sum_{k=1..n} (-n)^(n-k) * binomial(n,k) * binomial(n,k-1) for n > 0.at n=8A336728