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 | 2 |
| 2 | 5 |
| 3 | 18 |
| 4 | 70 |
| 5 | 293 |
| 6 | 1283 |
| 7 | 5808 |
| 8 | 26960 |
| 9 | 127628 |
| 10 | 613814 |
| 11 | 2990681 |
| 12 | 14730713 |
| 13 | 73229291 |
| 14 | 366936231 |
| 15 | 1851352820 |
| 16 | 9397497758 |
| 17 | 47957377934 |
| 18 | 245903408244 |
| 19 | 1266266092112 |
| 20 | 6545667052320 |
| 21 | 33954266444498 |
| 22 | 176689391245146 |