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 | 3 |
| 2 | 16 |
| 3 | 93 |
| 4 | 562 |
| 5 | 3473 |
| 6 | 21778 |
| 7 | 137980 |
| 8 | 880970 |
| 9 | 5658537 |
| 10 | 36519556 |
| 11 | 236618693 |
| 12 | 1538132224 |
| 13 | 10026362492 |
| 14 | 65513177704 |
| 15 | 428957009288 |
| 16 | 2813768603466 |
| 17 | 18486790962201 |
| 18 | 121634649321208 |
| 19 | 801330506737399 |
| 20 | 5285305708097522 |
| 21 | 34896814868837161 |
| 22 | 230631268849574378 |