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 | 3 |
| 2 | 11 |
| 3 | 50 |
| 4 | 273 |
| 5 | 1746 |
| 6 | 12823 |
| 7 | 106462 |
| 8 | 986689 |
| 9 | 10103074 |
| 10 | 113309991 |
| 11 | 1381835454 |
| 12 | 18209834849 |
| 13 | 257911743506 |
| 14 | 3907538236631 |
| 15 | 63066584719982 |
| 16 | 1080340925760129 |
| 17 | 19577690297352258 |
| 18 | 374214932301757255 |
| 19 | 7524626434657416286 |
| 20 | 158783753482817132065 |