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 | 21 |
| 2 | 441 |
| 3 | 3609 |
| 4 | 20662 |
| 5 | 139307 |
| 6 | 1181340 |
| 7 | 9908740 |
| 8 | 75877068 |
| 9 | 567455273 |
| 10 | 4366586742 |
| 11 | 34248998327 |
| 12 | 267095931282 |
| 13 | 2063862354490 |
| 14 | 15938318691269 |
| 15 | 123521439902876 |
| 16 | 958572046267137 |
| 17 | 7431458286122944 |
| 18 | 57564941872885645 |
| 19 | 445967087965474764 |