Number of vertices of type D at level n of the hyperbolic Pascal pyramid PP_(4,5).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =3a(5) =7a(6) =16a(7) =38a(8) =94a(9) =239a(10) =617a(11) =1605a(12) =4190a(13) =10956a(14) =28668a(15) =75037a(16) =196431a(17) =514243a(18) =1346284a(19) =3524594a(20) =9227482a(21) =24157835a(22) =63246005a(23) =165580161a(24) =433494458a(25) =1134903192a(26) =2971215096a(27) =7778742073a(28) =20365011099a(29) =53316291199