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 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 87 |
| 6 | 413 |
| 7 | 2213 |
| 8 | 13205 |
| 9 | 86828 |
| 10 | 623712 |
| 11 | 4859307 |
| 12 | 40810353 |
| 13 | 367525528 |
| 14 | 3532986232 |
| 15 | 36107260781 |
| 16 | 390938180027 |
| 17 | 4470065574970 |
| 18 | 53825174198772 |
| 19 | 680796406765054 |
| 20 | 9024180239004754 |
| 21 | 125096535241364056 |
| 22 | 1810074349321324370 |
| 23 | 27289548352480937756 |