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 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 29 |
| 7 | 81 |
| 8 | 229 |
| 9 | 696 |
| 10 | 2181 |
| 11 | 7045 |
| 12 | 23653 |
| 13 | 81433 |
| 14 | 288173 |
| 15 | 1046814 |
| 16 | 3887749 |
| 17 | 14768783 |
| 18 | 57275541 |
| 19 | 226462801 |
| 20 | 912443397 |
| 21 | 3741515804 |
| 22 | 15603500797 |
| 23 | 66134448329 |
| 24 | 284660214181 |
| 25 | 1243605590897 |
| 26 | 5511058189989 |
| 27 | 24760003963802 |
| 28 | 112726590916645 |