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.

A145021 a(n) = number of different positive integers that can be formed from different groupings of expressions of the form n op1 n op2 n op3 n, where each of op1, op2 and op3 are addition, subtraction, multiplication or division.

Table of values

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

List of values

[4, 10, 20, 25, 27, 29, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30]

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

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