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 | 13 |
| 2 | 113 |
| 3 | 925 |
| 4 | 6577 |
| 5 | 42205 |
| 6 | 252673 |
| 7 | 1405325 |
| 8 | 7259297 |
| 9 | 35372141 |
| 10 | 164379601 |
| 11 | 733618493 |
| 12 | 3146718929 |
| 13 | 12990499005 |
| 14 | 51718535393 |
| 15 | 198914813101 |
| 16 | 740760081985 |
| 17 | 2678069599181 |
| 18 | 9420136888369 |
| 19 | 32289213758941 |