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.

A249780 Product of lowest and highest prime factors of 2^n-1.

Table of values

n a(n)
2 9
3 49
4 15
5 961
6 21
7 16129
8 51
9 511
10 93
11 2047
12 39
13 67092481
14 381
15 1057
16 771
17 17179607041
18 219
19 274876858369
20 123
21 2359
22 2049
23 8388607
24 723
25 55831
26 24573
27 1838599
28 381
29 486737
30 993
31 4611686014132420609
32 196611
33 4196353
34 393213
35 3810551
36 327
37 137438953471
38 1572861
39 849583
40 185043

List of values

[9, 49, 15, 961, 21, 16129, 51, 511, 93, 2047, 39, 67092481, 381, 1057, 771, 17179607041, 219, 274876858369, 123, 2359, 2049, 8388607, 723, 55831, 24573, 1838599, 381, 486737, 993, 4611686014132420609, 196611, 4196353, 393213, 3810551, 327, 137438953471, 1572861, 849583, 185043]

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

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