Number of reduced words of length n in the Weyl group D_7.

Terms

a(0) =1a(1) =7a(2) =27a(3) =77a(4) =181a(5) =371a(6) =686a(7) =1169a(8) =1862a(9) =2800a(10) =4005a(11) =5481a(12) =7210a(13) =9149a(14) =11230a(15) =13363a(16) =15442a(17) =17353a(18) =18983a(19) =20230a(20) =21013a(21) =21280a(22) =21013a(23) =20230a(24) =18983a(25) =17353a(26) =15442a(27) =13363a(28) =11230a(29) =9149