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) |
|---|---|
| 1 | 12 |
| 2 | 144 |
| 3 | 883 |
| 4 | 4914 |
| 5 | 26723 |
| 6 | 140617 |
| 7 | 721597 |
| 8 | 3648942 |
| 9 | 18246880 |
| 10 | 90587254 |
| 11 | 447352515 |
| 12 | 2201344823 |
| 13 | 10804697625 |
| 14 | 52937908893 |
| 15 | 259040875255 |
| 16 | 1266429871446 |
| 17 | 6187499700062 |
| 18 | 30216983863723 |
| 19 | 147517894395275 |
| 20 | 720006607430081 |