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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 14 |
| 5 | 50 |
| 6 | 175 |
| 7 | 616 |
| 8 | 2163 |
| 9 | 7601 |
| 10 | 26703 |
| 11 | 93819 |
| 12 | 329615 |
| 13 | 1158052 |
| 14 | 4068623 |
| 15 | 14294449 |
| 16 | 50221212 |
| 17 | 176444054 |
| 18 | 619907431 |
| 19 | 2177943781 |
| 20 | 7651850657 |
| 21 | 26883530748 |
| 22 | 94450905714 |
| 23 | 331837870408 |
| 24 | 1165858298498 |
| 25 | 4096053203771 |
| 26 | 14390815650209 |
| 27 | 50559786403254 |