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 | 4 |
| 2 | 22 |
| 3 | 128 |
| 4 | 771 |
| 5 | 4744 |
| 6 | 29618 |
| 7 | 186880 |
| 8 | 1188679 |
| 9 | 7608764 |
| 10 | 48953224 |
| 11 | 316283264 |
| 12 | 2050706932 |
| 13 | 13336273528 |
| 14 | 86953633242 |
| 15 | 568221290496 |
| 16 | 3720529001823 |
| 17 | 24403423540348 |
| 18 | 160314652983158 |
| 19 | 1054635453261568 |
| 20 | 6946703172803003 |
| 21 | 45809043607167328 |
| 22 | 302395650703501688 |