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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.

A270836 Numbers k such that sigma(k-1) - phi(k-1) = (3*k-5)/2.

Table of values

n a(n)
1 3
2 5
3 9
4 11
5 17
6 33
7 65
8 129
9 231
10 257
11 513
12 1025
13 2049
14 4097
15 8193
16 16385
17 32769
18 65537
19 119831
20 131073
21 262145
22 524289
23 1048577
24 2097153
25 4194305
26 8388609
27 16777217
28 33554433
29 67108865
30 134217729
31 268435457
32 536870913
33 1073741825
34 2147483649
35 4294967297

List of values

[3, 5, 9, 11, 17, 33, 65, 129, 231, 257, 513, 1025, 2049, 4097, 8193, 16385, 32769, 65537, 119831, 131073, 262145, 524289, 1048577, 2097153, 4194305, 8388609, 16777217, 33554433, 67108865, 134217729, 268435457, 536870913, 1073741825, 2147483649, 4294967297]

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

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