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.
| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 18 |
| 2 | 80 |
| 3 | 316 |
| 4 | 1124 |
| 5 | 3976 |
| 6 | 13770 |
| 7 | 46398 |
| 8 | 155174 |
| 9 | 512700 |
| 10 | 1679218 |
| 11 | 5454768 |
| 12 | 17617664 |
| 13 | 56578816 |
| 14 | 180896064 |
| 15 | 576041630 |
| 16 | 1827788446 |
| 17 | 5781493590 |
| 18 | 18236550884 |
| 19 | 57379347420 |
| 20 | 180130119286 |
| 21 | 564319058202 |
| 22 | 1764618506934 |
| 23 | 5508483994106 |
| 24 | 17168384214168 |
| 25 | 53431296170784 |