Number of reduced words of length n in the Weyl group B_9.

Terms

a(0) =1a(1) =9a(2) =44a(3) =156a(4) =449a(5) =1113a(6) =2463a(7) =4983a(8) =9372a(9) =16588a(10) =27886a(11) =44846a(12) =69387a(13) =103763a(14) =150538a(15) =212538a(16) =292779a(17) =394371a(18) =520399a(19) =673783a(20) =857121a(21) =1072521a(22) =1321430a(23) =1604470a(24) =1921291a(25) =2270451a(26) =2649332a(27) =3054100a(28) =3479715a(29) =3919995