A058520 Sequences of B-trees of order 3 with n labeled leaves.
1, 1, 2, 4, 8, 17, 35, 73, 152, 316, 659, 1376, 2875, 6004, 12535, 26173, 54654, 114134, 238348, 497743, 1039432, 2170634, 4532949, 9466295, 19768943, 41284768, 86218046, 180056039, 376025957, 785286555, 1639979712, 3424906290
Offset: 0
Keywords
Programs
-
Maple
spec := [C, {B=Union(Z, Subst(M, B)), M=Union(Prod(Z,Z),Prod(Z,Z,Z)), C=Sequence(B)}]; [seq(combstruct[count](spec, size=n), n=0..40)];