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.

A119920 Number of rationals in [0, 1) having exactly n preperiodic bits, then exactly n periodic bits.

Table of values

n a(n)
1 1
2 4
3 24
4 96
5 480
6 1728
7 8064
8 30720
9 129024
10 506880
11 2095104
12 8232960
13 33546240
14 133152768
15 536248320
16 2139095040
17 8589803520
18 34285289472
19 137438429184
20 549212651520
21 2198882746368
22 8791793860608
23 35184363700224

List of values

[1, 4, 24, 96, 480, 1728, 8064, 30720, 129024, 506880, 2095104, 8232960, 33546240, 133152768, 536248320, 2139095040, 8589803520, 34285289472, 137438429184, 549212651520, 2198882746368, 8791793860608, 35184363700224]