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 | 10 |
| 3 | 40 |
| 4 | 193 |
| 5 | 1107 |
| 6 | 7412 |
| 7 | 56960 |
| 8 | 495055 |
| 9 | 4805327 |
| 10 | 51540462 |
| 11 | 605360184 |
| 12 | 7726837413 |
| 13 | 106484488843 |
| 14 | 1575591323104 |
| 15 | 24910186990320 |
| 16 | 419042540060243 |
| 17 | 7472730215908551 |
| 18 | 140804433625595626 |
| 19 | 2795108750920323336 |