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 | 3 |
| 3 | 7 |
| 4 | 30 |
| 5 | 137 |
| 6 | 1065 |
| 7 | 10307 |
| 8 | 130040 |
| 9 | 1927853 |
| 10 | 32809979 |
| 11 | 625303343 |
| 12 | 13178378742 |
| 13 | 304081128617 |
| 14 | 7623562484349 |
| 15 | 206343110670031 |
| 16 | 5996839161108904 |
| 17 | 186254714746749377 |
| 18 | 6156752738537004317 |
| 19 | 215810382975655205399 |
| 20 | 7995774673152799224930 |