Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
A162921
Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
Terms
- a(0) =1a(1) =4a(2) =12a(3) =36a(4) =102a(5) =288a(6) =816a(7) =2304a(8) =6510a(9) =18396a(10) =51972a(11) =146844a(12) =414894a(13) =1172232a(14) =3312024a(15) =9357768a(16) =26439366a(17) =74701620a(18) =211061436a(19) =596331540a(20) =1684871094a(21) =4760423280a(22) =13450067520a(23) =38001729168a(24) =107369826654a(25) =303361976844
External references
- oeis: A162921