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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 20 |
| 5 | 45 |
| 6 | 103 |
| 7 | 238 |
| 8 | 555 |
| 9 | 1305 |
| 10 | 3090 |
| 11 | 7362 |
| 12 | 17637 |
| 13 | 42460 |
| 14 | 102670 |
| 15 | 249246 |
| 16 | 607256 |
| 17 | 1484343 |
| 18 | 3639094 |
| 19 | 8946260 |
| 20 | 22048771 |
| 21 | 54467577 |
| 22 | 134842844 |
| 23 | 334493154 |
| 24 | 831296965 |
| 25 | 2069573632 |
| 26 | 5160747114 |
| 27 | 12888640503 |
| 28 | 32234749938 |
| 29 | 80728619175 |
| 30 | 202433907465 |