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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 23 |
| 7 | 60 |
| 8 | 170 |
| 9 | 496 |
| 10 | 1505 |
| 11 | 4665 |
| 12 | 14772 |
| 13 | 47415 |
| 14 | 154093 |
| 15 | 505394 |
| 16 | 1671009 |
| 17 | 5561274 |
| 18 | 18615687 |
| 19 | 62624016 |
| 20 | 211605003 |
| 21 | 717823582 |
| 22 | 2443711716 |
| 23 | 8345934897 |
| 24 | 28587110560 |
| 25 | 98181058020 |
| 26 | 338029066457 |
| 27 | 1166451261583 |
| 28 | 4033596172701 |
| 29 | 13975467586797 |
| 30 | 48509872173875 |