Number of reduced words of length n in the Weyl group B_18.

Terms

a(0) =1a(1) =18a(2) =170a(3) =1122a(4) =5813a(5) =25176a(6) =94791a(7) =318630a(8) =974643a(9) =2752112a(10) =7253764a(11) =18003544a(12) =42378246a(13) =95162260a(14) =204856291a(15) =424515042a(16) =849825768a(17) =1648470894a(18) =3106669575a(19) =5701318544a(20) =10209535182a(21) =17871860844a(22) =30631158960a(23) =51476623220a(24) =84931612739