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 | 2 |
| 3 | 7 |
| 4 | 41 |
| 5 | 376 |
| 6 | 5033 |
| 7 | 92821 |
| 8 | 2257166 |
| 9 | 69981919 |
| 10 | 2694447797 |
| 11 | 126128146156 |
| 12 | 7054258103921 |
| 13 | 464584757637001 |
| 14 | 35586641825705882 |
| 15 | 3136942184333040727 |
| 16 | 315295985573234822561 |
| 17 | 35843594275585750890976 |
| 18 | 4575961401477587844760793 |
| 19 | 651880406652100451820206941 |