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 | 3967 |
| 4 | 55063 |
| 5 | 728935 |
| 6 | 8942469 |
| 7 | 115505069 |
| 8 | 1476136671 |
| 9 | 18751133599 |
| 10 | 239558002631 |
| 11 | 3055238118019 |
| 12 | 38950706917793 |
| 13 | 496876286463839 |
| 14 | 6336882323606735 |
| 15 | 80816445128377245 |
| 16 | 1030742612403238579 |