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 | 1 |
| 3 | 3 |
| 4 | 5 |
| 5 | 18 |
| 6 | 35 |
| 7 | 136 |
| 8 | 285 |
| 9 | 1155 |
| 10 | 2530 |
| 11 | 10530 |
| 12 | 23751 |
| 13 | 100688 |
| 14 | 231880 |
| 15 | 996336 |
| 16 | 2330445 |
| 17 | 10116873 |
| 18 | 23950355 |
| 19 | 104819165 |
| 20 | 250543370 |
| 21 | 1103722620 |
| 22 | 2658968130 |
| 23 | 11777187240 |
| 24 | 28558343775 |
| 25 | 127067830773 |
| 26 | 309831575760 |
| 27 | 1383914371728 |
| 28 | 3390416787880 |
| 29 | 15194457001440 |