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.

A003407 Number of permutations of [n] with no 3-term arithmetic progression.

Table of values

n a(n)
0 1
1 1
2 2
3 4
4 10
5 20
6 48
7 104
8 282
9 496
10 1066
11 2460
12 6128
13 12840
14 29380
15 74904
16 212728
17 368016
18 659296
19 1371056
20 2937136
21 6637232
22 15616616
23 38431556
24 96547832
25 198410168
26 419141312
27 941812088
28 2181990978
29 5624657008
30 14765405996
31 41918682488
32 121728075232

List of values

[1, 1, 2, 4, 10, 20, 48, 104, 282, 496, 1066, 2460, 6128, 12840, 29380, 74904, 212728, 368016, 659296, 1371056, 2937136, 6637232, 15616616, 38431556, 96547832, 198410168, 419141312, 941812088, 2181990978, 5624657008, 14765405996, 41918682488, 121728075232]

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

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