Number of reduced words of length n in Coxeter group on 21 generators S_i with relations (S_i)^2 = (S_i S_j)^6 = I.
A163977
Number of reduced words of length n in Coxeter group on 21 generators S_i with relations (S_i)^2 = (S_i S_j)^6 = I.
Terms
- a(0) =1a(1) =21a(2) =420a(3) =8400a(4) =168000a(5) =3360000a(6) =67199790a(7) =1343991600a(8) =26879748210a(9) =537593288400
External references
- oeis: A163977