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.

A349919 Number of transitive relations on an n-set with exactly two ordered pairs.

Table of values

n a(n)
0 0
1 0
2 5
3 27
4 90
5 230
6 495
7 945
8 1652
9 2700
10 4185
11 6215
12 8910
13 12402
14 16835
15 22365
16 29160
17 37400
18 47277
19 58995
20 72770
21 88830
22 107415
23 128777
24 153180
25 180900
26 212225
27 247455
28 286902
29 330890
30 379755
31 433845
32 493520
33 559152
34 631125
35 709835
36 795690
37 889110
38 990527
39 1100385
40 1219140
41 1347260
42 1485225
43 1633527
44 1792670

List of values

[0, 0, 5, 27, 90, 230, 495, 945, 1652, 2700, 4185, 6215, 8910, 12402, 16835, 22365, 29160, 37400, 47277, 58995, 72770, 88830, 107415, 128777, 153180, 180900, 212225, 247455, 286902, 330890, 379755, 433845, 493520, 559152, 631125, 709835, 795690, 889110, 990527, 1100385, 1219140, 1347260, 1485225, 1633527, 1792670]

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

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