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 | 6 |
| 2 | 33 |
| 3 | 189 |
| 4 | 1107 |
| 5 | 6588 |
| 6 | 39663 |
| 7 | 240894 |
| 8 | 1473147 |
| 9 | 9058554 |
| 10 | 55954395 |
| 11 | 346934745 |
| 12 | 2157989445 |
| 13 | 13459891500 |
| 14 | 84152389833 |
| 15 | 527224251861 |
| 16 | 3309194474451 |
| 17 | 20804569738218 |
| 18 | 130987600581699 |
| 19 | 825796890644895 |
| 20 | 5212349717906889 |
| 21 | 32935490120006604 |
| 22 | 208316726580941037 |