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 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 10 |
| 5 | 29 |
| 6 | 72 |
| 7 | 190 |
| 8 | 520 |
| 9 | 1413 |
| 10 | 3888 |
| 11 | 10839 |
| 12 | 30421 |
| 13 | 86218 |
| 14 | 246499 |
| 15 | 708931 |
| 16 | 2050584 |
| 17 | 5962100 |
| 18 | 17407554 |
| 19 | 51019081 |
| 20 | 150052163 |
| 21 | 442677295 |
| 22 | 1309668356 |
| 23 | 3884884796 |
| 24 | 11551622175 |
| 25 | 34425468793 |
| 26 | 102807253860 |
| 27 | 307617338332 |
| 28 | 922112808168 |
| 29 | 2768808168311 |
| 30 | 8327028966970 |