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) |
|---|---|
| 1 | 2 |
| 2 | 72 |
| 3 | 1442 |
| 4 | 20260 |
| 5 | 220250 |
| 6 | 1958460 |
| 7 | 14768810 |
| 8 | 96900810 |
| 9 | 563873400 |
| 10 | 2953859370 |
| 11 | 14097919968 |
| 12 | 61908797418 |
| 13 | 252208679268 |
| 14 | 959882556570 |
| 15 | 3433533723900 |
| 16 | 11603837100660 |
| 17 | 37221177046410 |
| 18 | 113779617228060 |
| 19 | 332648955112250 |
| 20 | 933146517188760 |
| 21 | 2518877938240202 |