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 | 5 |
| 3 | 33 |
| 4 | 282 |
| 5 | 2938 |
| 6 | 36029 |
| 7 | 507440 |
| 8 | 8058990 |
| 9 | 142315830 |
| 10 | 2763775025 |
| 11 | 58498072273 |
| 12 | 1339545500214 |
| 13 | 32980132065364 |
| 14 | 868417100538399 |
| 15 | 24344702489881998 |
| 16 | 723694354351500431 |
| 17 | 22733368105181643193 |
| 18 | 752291980101845144878 |
| 19 | 26153153055424960528533 |