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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.

A322442 Number of pairs of set partitions of {1,...,n} where every block of one is a subset or superset of some block of the other.

Table of values

n a(n)
0 1
1 1
2 4
3 25
4 195
5 1894
6 22159
7 303769
8 4790858
9 85715595
10 1720097275
11 38355019080
12 942872934661
13 25383601383937
14 744118939661444
15 23635548141900445
16 809893084668253151
17 29822472337116844174
18 1175990509568611058299
19 49504723853840395163221
20 2218388253903492656783562

List of values

[1, 1, 4, 25, 195, 1894, 22159, 303769, 4790858, 85715595, 1720097275, 38355019080, 942872934661, 25383601383937, 744118939661444, 23635548141900445, 809893084668253151, 29822472337116844174, 1175990509568611058299, 49504723853840395163221, 2218388253903492656783562]

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

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