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 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 29 |
| 5 | 98 |
| 6 | 316 |
| 7 | 1043 |
| 8 | 3536 |
| 9 | 12083 |
| 10 | 41168 |
| 11 | 139750 |
| 12 | 473824 |
| 13 | 1607014 |
| 14 | 5453022 |
| 15 | 18506947 |
| 16 | 62808496 |
| 17 | 213144034 |
| 18 | 723295969 |
| 19 | 2454483506 |
| 20 | 8329290739 |
| 21 | 28265565587 |
| 22 | 95919580313 |
| 23 | 325504019213 |
| 24 | 1104600373788 |
| 25 | 3748469764612 |
| 26 | 12720462563684 |
| 27 | 43166996581876 |