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.

A110045 Number of hierarchical orderings ("societies") of n unlabeled elements ("individuals") with at least two occupied levels.

Table of values

n a(n)
0 1
1 0
2 1
3 3
4 8
5 18
6 45
7 102
8 245
9 565
10 1324
11 3049
12 7066
13 16199
14 37187
15 84887
16 193532
17 439600
18 996818
19 2253941
20 5086980
21 11454778
22 25746467
23 57756522
24 129342179
25 289153474
26 645399011
27 1438308839
28 3200671082
29 7112360474
30 15783402471
31 34980122720
32 77428353682

List of values

[1, 0, 1, 3, 8, 18, 45, 102, 245, 565, 1324, 3049, 7066, 16199, 37187, 84887, 193532, 439600, 996818, 2253941, 5086980, 11454778, 25746467, 57756522, 129342179, 289153474, 645399011, 1438308839, 3200671082, 7112360474, 15783402471, 34980122720, 77428353682]