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 | 4 |
| 2 | 89 |
| 3 | 1566 |
| 4 | 20527 |
| 5 | 183310 |
| 6 | 1347565 |
| 7 | 8984158 |
| 8 | 56952323 |
| 9 | 351661806 |
| 10 | 2141759809 |
| 11 | 12950960686 |
| 12 | 78020943223 |
| 13 | 469112191342 |
| 14 | 2817757426037 |
| 15 | 16916183927550 |
| 16 | 101527228990219 |
| 17 | 609257523135022 |
| 18 | 3655839340823305 |
| 19 | 21935955102434638 |