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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 64 |
| 5 | 341 |
| 6 | 1913 |
| 7 | 11132 |
| 8 | 66573 |
| 9 | 406653 |
| 10 | 2526351 |
| 11 | 15913347 |
| 12 | 101396034 |
| 13 | 652378120 |
| 14 | 4232439734 |
| 15 | 27657380019 |
| 16 | 181872596607 |
| 17 | 1202641671293 |
| 18 | 7991878198287 |
| 19 | 53343146808137 |
| 20 | 357464739709920 |
| 21 | 2404073823950915 |