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 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 44 |
| 6 | 146 |
| 7 | 530 |
| 8 | 1975 |
| 9 | 7314 |
| 10 | 27262 |
| 11 | 102802 |
| 12 | 390138 |
| 13 | 1486064 |
| 14 | 5682756 |
| 15 | 21812436 |
| 16 | 83976075 |
| 17 | 324115550 |
| 18 | 1253795510 |
| 19 | 4859960402 |
| 20 | 18871869302 |
| 21 | 73398851448 |
| 22 | 285882923196 |
| 23 | 1114943553308 |
| 24 | 4353426835238 |
| 25 | 17016813133124 |
| 26 | 66581653586476 |
| 27 | 260750813149140 |
| 28 | 1022023318047220 |