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 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 45 |
| 4 | 166 |
| 5 | 505 |
| 6 | 1342 |
| 7 | 3224 |
| 8 | 7161 |
| 9 | 14938 |
| 10 | 29602 |
| 11 | 56211 |
| 12 | 102973 |
| 13 | 182963 |
| 14 | 316694 |
| 15 | 535947 |
| 16 | 889454 |
| 17 | 1451305 |
| 18 | 2333356 |
| 19 | 3703510 |
| 20 | 5812615 |
| 21 | 9034001 |
| 22 | 13921551 |
| 23 | 21294946 |
| 24 | 32364747 |
| 25 | 48915873 |
| 26 | 73576675 |
| 27 | 110213470 |
| 28 | 164508959 |
| 29 | 244810154 |
| 30 | 363371304 |
| 31 | 538175735 |