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 | 10 |
| 2 | 80 |
| 3 | 660 |
| 4 | 5430 |
| 5 | 44692 |
| 6 | 367826 |
| 7 | 3027314 |
| 8 | 24915652 |
| 9 | 205062892 |
| 10 | 1687725824 |
| 11 | 13890462738 |
| 12 | 114322452324 |
| 13 | 940906242802 |
| 14 | 7743925534706 |
| 15 | 63734705924048 |
| 16 | 524554726284436 |
| 17 | 4317234336897124 |
| 18 | 35532064407664766 |
| 19 | 292438978880594940 |