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 | 4 |
| 2 | 75 |
| 3 | 1016 |
| 4 | 15615 |
| 5 | 279924 |
| 6 | 5764787 |
| 7 | 134217712 |
| 8 | 3486784383 |
| 9 | 99999999980 |
| 10 | 3138428376699 |
| 11 | 106993205379048 |
| 12 | 3937376385699263 |
| 13 | 155568095557812196 |
| 14 | 6568408355712890595 |
| 15 | 295147905179352825824 |
| 16 | 14063084452067724990975 |
| 17 | 708235345355337676357596 |
| 18 | 37589973457545958193355563 |