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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 8 |
| 6 | 20 |
| 7 | 66 |
| 8 | 196 |
| 9 | 688 |
| 10 | 2358 |
| 11 | 8840 |
| 12 | 33506 |
| 13 | 134376 |
| 14 | 550498 |
| 15 | 2350348 |
| 16 | 10273110 |
| 17 | 46413536 |
| 18 | 214598786 |
| 19 | 1020359628 |
| 20 | 4959234118 |
| 21 | 24699168280 |
| 22 | 125571468666 |
| 23 | 652484852756 |
| 24 | 3456224649758 |
| 25 | 18673351714128 |
| 26 | 102717737562850 |