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 | 5 |
| 1 | 5 |
| 2 | 9 |
| 3 | 25 |
| 4 | 97 |
| 5 | 481 |
| 6 | 2881 |
| 7 | 20161 |
| 8 | 161281 |
| 9 | 1451521 |
| 10 | 14515201 |
| 11 | 159667201 |
| 12 | 1916006401 |
| 13 | 24908083201 |
| 14 | 348713164801 |
| 15 | 5230697472001 |
| 16 | 83691159552001 |
| 17 | 1422749712384001 |
| 18 | 25609494822912001 |
| 19 | 486580401635328001 |
| 20 | 9731608032706560001 |
| 21 | 204363768686837760001 |