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.

A090327 Number of rules of a context-free grammar in Chomsky normal form that generates all permutations of n symbols.

Table of values

n a(n)
1 1
2 4
3 11
4 30
5 83
6 234
7 671
8 1950
9 5723
10 16914
11 50231
12 149670
13 446963
14 1336794
15 4002191
16 11990190
17 35937803
18 107747874
19 323112551
20 969075510
21 2906702243
22 8719058154
23 26155077311
24 78461037630
25 235374724283
26 706107395634
27 2118288632471
28 6354798788550

List of values

[1, 4, 11, 30, 83, 234, 671, 1950, 5723, 16914, 50231, 149670, 446963, 1336794, 4002191, 11990190, 35937803, 107747874, 323112551, 969075510, 2906702243, 8719058154, 26155077311, 78461037630, 235374724283, 706107395634, 2118288632471, 6354798788550]

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

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