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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.

A380634 Number of unlabeled 2,3 cacti (triangular cacti with bridges) with n triangles and every node contained in exactly one triangle.

Table of values

n a(n)
0 1
1 1
2 1
3 2
4 6
5 18
6 66
7 265
8 1140
9 5186
10 24588
11 120062
12 600884
13 3066490
14 15907266
15 83665520
16 445317808
17 2394928214
18 12997988041
19 71116953074
20 391931826699
21 2174062325068
22 12130745830640
23 68049392678632
24 383601371168527
25 2172093593344465
26 12349917974708867

List of values

[1, 1, 1, 2, 6, 18, 66, 265, 1140, 5186, 24588, 120062, 600884, 3066490, 15907266, 83665520, 445317808, 2394928214, 12997988041, 71116953074, 391931826699, 2174062325068, 12130745830640, 68049392678632, 383601371168527, 2172093593344465, 12349917974708867]

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

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