Number of reduced words of length n in the Weyl group B_19.

Terms

a(0) =1a(1) =19a(2) =189a(3) =1311a(4) =7124a(5) =32300a(6) =127091a(7) =445721a(8) =1420364a(9) =4172476a(10) =11426240a(11) =29429784a(12) =71808030a(13) =166970290a(14) =371826581a(15) =796341623a(16) =1646167391a(17) =3294638285a(18) =6401307860a(19) =12102626404a(20) =22312161586a(21) =40184022430a(22) =70815181390a(23) =122291804610a(24) =207223417349a(25) =344959019207a(26) =564743768579