cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A228404 The number of complete binary trees with bicolored twigs. A twig is a vertex with one child on the boundary and the other child having no descendants.

Table of values

n a(n)
0 1
1 2
2 8
3 24
4 76
5 249
6 836
7 2860
8 9932
9 34918
10 124032
11 444448
12 1604664
13 5831765
14 21316860
15 78319140
16 289064460
17 1071275370
18 3984871440
19 14872552560
20 55678270440
21 209027020410
22 786750047304
23 2968257334104
24 11223268563896
25 42522737574604
26 161415556062656
27 613813414982656

List of values

[1, 2, 8, 24, 76, 249, 836, 2860, 9932, 34918, 124032, 444448, 1604664, 5831765, 21316860, 78319140, 289064460, 1071275370, 3984871440, 14872552560, 55678270440, 209027020410, 786750047304, 2968257334104, 11223268563896, 42522737574604, 161415556062656, 613813414982656]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.