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.

A058809 The sequence lambda(3,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly three starting and/or finishing points.

Table of values

n a(n)
0 0
1 0
2 6
3 24
4 78
5 240
6 726
7 2184
8 6558
9 19680
10 59046
11 177144
12 531438
13 1594320
14 4782966
15 14348904
16 43046718
17 129140160
18 387420486
19 1162261464
20 3486784398
21 10460353200
22 31381059606
23 94143178824
24 282429536478
25 847288609440

List of values

[0, 0, 6, 24, 78, 240, 726, 2184, 6558, 19680, 59046, 177144, 531438, 1594320, 4782966, 14348904, 43046718, 129140160, 387420486, 1162261464, 3486784398, 10460353200, 31381059606, 94143178824, 282429536478, 847288609440]

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

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