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 | 4 |
| 2 | 81 |
| 3 | 328 |
| 4 | 6641 |
| 5 | 26892 |
| 6 | 544481 |
| 7 | 2204816 |
| 8 | 44640801 |
| 9 | 180768020 |
| 10 | 3660001201 |
| 11 | 14820772824 |
| 12 | 300075457681 |
| 13 | 1215122603548 |
| 14 | 24602527528641 |
| 15 | 99625232718112 |
| 16 | 2017107181890881 |
| 17 | 8168053960281636 |
| 18 | 165378186387523601 |
| 19 | 669680799510376040 |