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.

A036239 Number of 2-element intersecting families of an n-element set; number of 2-way interactions when 2 subsets of power set on {1..n} are chosen at random.

Table of values

n a(n)
1 0
2 2
3 15
4 80
5 375
6 1652
7 7035
8 29360
9 120975
10 494252
11 2007555
12 8120840
13 32753175
14 131818052
15 529680075
16 2125927520
17 8525298975
18 34165897052
19 136857560595
20 548011897400
21 2193792030375
22 8780400395252
23 35137296305115
24 140596265198480

List of values

[0, 2, 15, 80, 375, 1652, 7035, 29360, 120975, 494252, 2007555, 8120840, 32753175, 131818052, 529680075, 2125927520, 8525298975, 34165897052, 136857560595, 548011897400, 2193792030375, 8780400395252, 35137296305115, 140596265198480]

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

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