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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 40 |
| 5 | 123 |
| 6 | 395 |
| 7 | 1227 |
| 8 | 3851 |
| 9 | 11944 |
| 10 | 37032 |
| 11 | 114144 |
| 12 | 351040 |
| 13 | 1075316 |
| 14 | 3285398 |
| 15 | 10007731 |
| 16 | 30409157 |
| 17 | 92169561 |
| 18 | 278738219 |
| 19 | 841132013 |
| 20 | 2533138770 |
| 21 | 7614144053 |
| 22 | 22845435104 |
| 23 | 68427663680 |
| 24 | 204623945617 |
| 25 | 610951554377 |
| 26 | 1821438443615 |
| 27 | 5422608839874 |
| 28 | 16121857331124 |