a(n) is the number of distinct reduced words of length n in the Coxeter group of "Apollonian reflections" in three dimensions.
A154638
a(n) is the number of distinct reduced words of length n in the Coxeter group of "Apollonian reflections" in three dimensions.
Terms
- a(0) =1a(1) =5a(2) =20a(3) =70a(4) =240a(5) =810a(6) =2730a(7) =9180a(8) =30870a(9) =103770a(10) =348840a(11) =1172610a(12) =3941730a(13) =13249980a(14) =44539470a(15) =149717970a(16) =503272440a(17) =1691734410a(18) =5686712730a(19) =19115706780a(20) =64256852070a(21) =215997400170a(22) =726068516040
External references
- oeis: A154638