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 | 6 |
| 4 | 19 |
| 5 | 47 |
| 6 | 140 |
| 7 | 374 |
| 8 | 1082 |
| 9 | 2998 |
| 10 | 8574 |
| 11 | 24130 |
| 12 | 68876 |
| 13 | 195587 |
| 14 | 559076 |
| 15 | 1596651 |
| 16 | 4575978 |
| 17 | 13122219 |
| 18 | 37711998 |
| 19 | 108488765 |
| 20 | 312577827 |
| 21 | 901531937 |
| 22 | 2603264050 |
| 23 | 7524331268 |
| 24 | 21768850808 |
| 25 | 63032844756 |
| 26 | 182662328945 |
| 27 | 529722408615 |
| 28 | 1537261773438 |