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.

A242832 Semiprimes of the form 2^k - 1 or 2^k - 2.

Table of values

n a(n)
1 6
2 14
3 15
4 62
5 254
6 511
7 2047
8 16382
9 262142
10 1048574
11 8388607
12 4294967294
13 137438953471
14 562949953421311
15 576460752303423487
16 4611686018427387902
17 147573952589676412927
18 9671406556917033397649407
19 1237940039285380274899124222
20 158456325028528675187087900671

List of values

[6, 14, 15, 62, 254, 511, 2047, 16382, 262142, 1048574, 8388607, 4294967294, 137438953471, 562949953421311, 576460752303423487, 4611686018427387902, 147573952589676412927, 9671406556917033397649407, 1237940039285380274899124222, 158456325028528675187087900671]

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

Content is available under The OEIS End-User License Agreement.