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 | 3 |
| 2 | 9 |
| 3 | 9 |
| 4 | 33 |
| 5 | 53 |
| 6 | 183 |
| 7 | 395 |
| 8 | 1249 |
| 9 | 3141 |
| 10 | 9459 |
| 11 | 25655 |
| 12 | 75639 |
| 13 | 212943 |
| 14 | 623093 |
| 15 | 1787609 |
| 16 | 5222369 |
| 17 | 15134933 |
| 18 | 44250051 |
| 19 | 128996855 |
| 20 | 377748883 |
| 21 | 1105350731 |
| 22 | 3242546393 |
| 23 | 9513228125 |
| 24 | 27953744695 |
| 25 | 82176836303 |
| 26 | 241834027353 |
| 27 | 712070156205 |