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 | 32 |
| 3 | 229 |
| 4 | 1845 |
| 5 | 14320 |
| 6 | 112485 |
| 7 | 880163 |
| 8 | 6895792 |
| 9 | 54003765 |
| 10 | 422983905 |
| 11 | 3312866080 |
| 12 | 25947198337 |
| 13 | 203223953179 |
| 14 | 1591695681488 |
| 15 | 12466511517581 |
| 16 | 97640484615909 |
| 17 | 764741896529104 |
| 18 | 5989627994067061 |
| 19 | 46912093390144139 |
| 20 | 367425909133064576 |
| 21 | 2877761124002870925 |