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.

A111776 Triangle read by rows: number of idempotent order-preserving partial transformations (of an n-element chain) of waist k (waist(alpha) = max(Im(alpha))).

Table of values

n a(n)
0 1
1 1
2 1
3 1
4 2
5 3
6 1
7 4
8 6
9 10
10 1
11 8
12 12
13 20
14 35
15 1
16 16
17 24
18 40
19 70
20 125
21 1
22 32
23 48
24 80
25 140
26 250
27 450
28 1
29 64
30 96
31 160
32 280
33 500
34 900
35 1625

List of values

[1, 1, 1, 1, 2, 3, 1, 4, 6, 10, 1, 8, 12, 20, 35, 1, 16, 24, 40, 70, 125, 1, 32, 48, 80, 140, 250, 450, 1, 64, 96, 160, 280, 500, 900, 1625]