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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 8 |
| 7 | 27 |
| 8 | 83 |
| 9 | 292 |
| 10 | 944 |
| 11 | 3279 |
| 12 | 11291 |
| 13 | 38992 |
| 14 | 138066 |
| 15 | 490248 |
| 16 | 1757360 |
| 17 | 6347321 |
| 18 | 22998089 |
| 19 | 83780199 |
| 20 | 306819363 |
| 21 | 1128999790 |
| 22 | 4174251748 |
| 23 | 15507225620 |
| 24 | 57767819903 |
| 25 | 215327188611 |
| 26 | 803901214851 |
| 27 | 3013081897103 |
| 28 | 11331883386143 |
| 29 | 42737620941612 |