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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.

A217836 a(n) is largest semiprime < 2*a(n-1), with a(1) = 4.

Table of values

n a(n)
1 4
2 6
3 10
4 15
5 26
6 51
7 95
8 187
9 371
10 737
11 1473
12 2942
13 5878
14 11755
15 23507
16 47013
17 94021
18 188041
19 376069
20 752135
21 1504261
22 3008503
23 6017001
24 12034001
25 24068001
26 48135995
27 96271987
28 192543973
29 385087943
30 770175883
31 1540351763
32 3080703523
33 6161407045
34 12322814089
35 24645628171

List of values

[4, 6, 10, 15, 26, 51, 95, 187, 371, 737, 1473, 2942, 5878, 11755, 23507, 47013, 94021, 188041, 376069, 752135, 1504261, 3008503, 6017001, 12034001, 24068001, 48135995, 96271987, 192543973, 385087943, 770175883, 1540351763, 3080703523, 6161407045, 12322814089, 24645628171]

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

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