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 | 3 |
| 3 | 4 |
| 4 | 12 |
| 5 | 25 |
| 6 | 52 |
| 7 | 121 |
| 8 | 261 |
| 9 | 576 |
| 10 | 1280 |
| 11 | 2809 |
| 12 | 6204 |
| 13 | 13689 |
| 14 | 30167 |
| 15 | 66564 |
| 16 | 146804 |
| 17 | 323761 |
| 18 | 714136 |
| 19 | 1575025 |
| 20 | 3473817 |
| 21 | 7661824 |
| 22 | 16898560 |
| 23 | 37271025 |
| 24 | 82203912 |
| 25 | 181306225 |
| 26 | 399883707 |
| 27 | 881971204 |
| 28 | 1945248444 |
| 29 | 4290381001 |
| 30 | 9462732780 |