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 | 2 |
| 2 | 3 |
| 3 | 6 |
| 4 | 18 |
| 5 | 79 |
| 6 | 463 |
| 7 | 3396 |
| 8 | 30073 |
| 9 | 314037 |
| 10 | 3796561 |
| 11 | 52332869 |
| 12 | 812013163 |
| 13 | 14029926801 |
| 14 | 267461387125 |
| 15 | 5581705418715 |
| 16 | 126657160962835 |
| 17 | 3106644875467396 |
| 18 | 81943115662983569 |
| 19 | 2313753122033185373 |
| 20 | 69654973411269008826 |
| 21 | 2227679407193350385775 |