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 | 3 |
| 3 | 8 |
| 4 | 22 |
| 5 | 62 |
| 6 | 182 |
| 7 | 560 |
| 8 | 1822 |
| 9 | 6316 |
| 10 | 23467 |
| 11 | 93762 |
| 12 | 402989 |
| 13 | 1858904 |
| 14 | 9165303 |
| 15 | 48065800 |
| 16 | 266791060 |
| 17 | 1560140592 |
| 18 | 9573440644 |
| 19 | 61431041813 |
| 20 | 411006873603 |
| 21 | 2859978776644 |
| 22 | 20653331408062 |
| 23 | 154494203986783 |
| 24 | 1195107012223439 |
| 25 | 9546189429869925 |
| 26 | 78632580076861376 |
| 27 | 667111706008969377 |