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 | 3 |
| 2 | 12 |
| 3 | 49 |
| 4 | 200 |
| 5 | 816 |
| 6 | 3329 |
| 7 | 13581 |
| 8 | 55405 |
| 9 | 226030 |
| 10 | 922111 |
| 11 | 3761840 |
| 12 | 15346786 |
| 13 | 62608681 |
| 14 | 255418101 |
| 15 | 1042002567 |
| 16 | 4250949112 |
| 17 | 17342153393 |
| 18 | 70748973084 |
| 19 | 288627200960 |
| 20 | 1177482265857 |
| 21 | 4803651498529 |
| 22 | 19596955630177 |