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 | 1 |
| 3 | 3 |
| 4 | 23 |
| 5 | 319 |
| 6 | 6999 |
| 7 | 223725 |
| 8 | 9838405 |
| 9 | 570440733 |
| 10 | 42203958765 |
| 11 | 3882243620535 |
| 12 | 434771830226307 |
| 13 | 58255737747374083 |
| 14 | 9203989127308306571 |
| 15 | 1693477639607917108953 |
| 16 | 359008305377998952818761 |
| 17 | 86878355403079952880852217 |
| 18 | 23804317478591173659253678809 |
| 19 | 7331644401028481860472940727371 |