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 | 2 |
| 2 | 41 |
| 3 | 84 |
| 4 | 1721 |
| 5 | 3526 |
| 6 | 72241 |
| 7 | 148008 |
| 8 | 3032401 |
| 9 | 6212810 |
| 10 | 127288601 |
| 11 | 260790012 |
| 12 | 5343088841 |
| 13 | 10946967694 |
| 14 | 224282442721 |
| 15 | 459511853136 |
| 16 | 9414519505441 |
| 17 | 19288550864018 |
| 18 | 395185536785801 |
| 19 | 809659624435620 |
| 20 | 16588378025498201 |
| 21 | 33986415675432022 |