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.

A210912 Number of transitive reflexive early confluent binary relations R on n labeled elements where |{y : xRy}| <= 4 for all x.

Table of values

n a(n)
0 1
1 1
2 4
3 26
4 243
5 2451
6 29922
7 420841
8 6692163
9 118170959
10 2296688956
11 48661358989
12 1115587992521
13 27499790373121
14 725031761113038
15 20351018228318061
16 605726610363853513
17 19050158234570819809
18 631097355371645795620
19 21961423837720097681425

List of values

[1, 1, 4, 26, 243, 2451, 29922, 420841, 6692163, 118170959, 2296688956, 48661358989, 1115587992521, 27499790373121, 725031761113038, 20351018228318061, 605726610363853513, 19050158234570819809, 631097355371645795620, 21961423837720097681425]

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

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