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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.

A083535 A version of the Chebyshev function theta(n): a(n) = ceiling(Sum_{primes p <= n } log(p)).

Table of values

n a(n)
1 0
2 1
3 2
4 2
5 4
6 4
7 6
8 6
9 6
10 6
11 8
12 8
13 11
14 11
15 11
16 11
17 14
18 14
19 17
20 17
21 17
22 17
23 20
24 20
25 20
26 20
27 20
28 20
29 23
30 23
31 27
32 27
33 27
34 27
35 27
36 27
37 30
38 30
39 30
40 30
41 34
42 34
43 38
44 38
45 38
46 38
47 41
48 41
49 41
50 41
51 41
52 41
53 45
54 45
55 45
56 45
57 45
58 45
59 50
60 50
61 54
62 54
63 54
64 54
65 54
66 54
67 58
68 58
69 58
70 58
71 62
72 62
73 66
74 66
75 66
76 66

List of values

[0, 1, 2, 2, 4, 4, 6, 6, 6, 6, 8, 8, 11, 11, 11, 11, 14, 14, 17, 17, 17, 17, 20, 20, 20, 20, 20, 20, 23, 23, 27, 27, 27, 27, 27, 27, 30, 30, 30, 30, 34, 34, 38, 38, 38, 38, 41, 41, 41, 41, 41, 41, 45, 45, 45, 45, 45, 45, 50, 50, 54, 54, 54, 54, 54, 54, 58, 58, 58, 58, 62, 62, 66, 66, 66, 66]

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