Number of vertices of type B at level n of the hyperbolic Pascal pyramid.

Terms

a(0) =0a(1) =0a(2) =0a(3) =3a(4) =12a(5) =36a(6) =99a(7) =264a(8) =696a(9) =1827a(10) =4788a(11) =12540a(12) =32835a(13) =85968a(14) =225072a(15) =589251a(16) =1542684a(17) =4038804a(18) =10573731a(19) =27682392a(20) =72473448a(21) =189737955a(22) =496740420a(23) =1300483308a(24) =3404709507a(25) =8913645216a(26) =23336226144a(27) =61095033219a(28) =159948873516a(29) =418751587332