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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 21 |
| 4 | 214 |
| 5 | 3004 |
| 6 | 53696 |
| 7 | 1169220 |
| 8 | 30017582 |
| 9 | 887835091 |
| 10 | 29728120594 |
| 11 | 1111619802614 |
| 12 | 45914106227815 |
| 13 | 2076062017348677 |
| 14 | 101996651482313080 |
| 15 | 5410363994433018486 |
| 16 | 308174409706787225523 |
| 17 | 18760485689929220881741 |
| 18 | 1215547422537201878074293 |
| 19 | 83520534389622385511232635 |