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 | 7 |
| 2 | 42 |
| 3 | 245 |
| 4 | 1421 |
| 5 | 8232 |
| 6 | 47677 |
| 7 | 276115 |
| 8 | 1599066 |
| 9 | 9260657 |
| 10 | 53631137 |
| 11 | 310593360 |
| 12 | 1798735561 |
| 13 | 10416995407 |
| 14 | 60327818922 |
| 15 | 349375764605 |
| 16 | 2023335619781 |
| 17 | 11717718986232 |
| 18 | 67860683565157 |
| 19 | 393000752052475 |
| 20 | 2275980479411226 |
| 21 | 13180858091511257 |
| 22 | 76334143284700217 |