A296689 - cp's OEIS frontend

A296689 Let phi be the one-to-one mapping between binary trees and natural numbers described in the Tychonievich link. Let a(n) = min({phi^{-1}(t)| size(t)=n}); i.e., a(n) is the rank -- starting from 0 -- of the first tree the size of which is n.

n	a(n)
0	0
1	1
2	2
3	4
4	7
5	13
6	24
7	30
8	54
9	64
10	124
11	244
12	383
13	503
14	981
15	1021
16	1981
17	3901
18	6137
19	8057
20	13649
21	16369
22	32689
23	65329
24	98230
25	130870
26	229312
27	261952
28	491516
29	524156
30	1046388
31	1048564
32	2093044
33	4182004
34	8359924
35	16715764
36	25141220
37	33497060
38	58703812
39	67059652
40	125828996
41	134184836
42	259487492
43	268435204
44	536866564
45	1073729284

[0, 1, 2, 4, 7, 13, 24, 30, 54, 64, 124, 244, 383, 503, 981, 1021, 1981, 3901, 6137, 8057, 13649, 16369, 32689, 65329, 98230, 130870, 229312, 261952, 491516, 524156, 1046388, 1048564, 2093044, 4182004, 8359924, 16715764, 25141220, 33497060, 58703812, 67059652, 125828996, 134184836, 259487492, 268435204, 536866564, 1073729284]

cp's OEIS Frontend

A296689 Let phi be the one-to-one mapping between binary trees and natural numbers described in the Tychonievich link. Let a(n) = min({phi^{-1}(t)| size(t)=n}); i.e., a(n) is the rank -- starting from 0 -- of the first tree the size of which is n.

Table of values

List of values