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 | 1 |
| 2 | 3 |
| 3 | 19 |
| 4 | 190 |
| 5 | 2574 |
| 6 | 43922 |
| 7 | 903986 |
| 8 | 21784659 |
| 9 | 601478195 |
| 10 | 18715354049 |
| 11 | 647834803569 |
| 12 | 24688869993252 |
| 13 | 1027073272425876 |
| 14 | 46309250293477020 |
| 15 | 2249435671825385244 |
| 16 | 117101538463333719891 |
| 17 | 6503918951175618656403 |