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 | 6 |
| 2 | 31 |
| 3 | 156 |
| 4 | 785 |
| 5 | 3954 |
| 6 | 19919 |
| 7 | 100344 |
| 8 | 505489 |
| 9 | 2546430 |
| 10 | 12827791 |
| 11 | 64620756 |
| 12 | 325530881 |
| 13 | 1639881066 |
| 14 | 8260997855 |
| 15 | 41615265264 |
| 16 | 209639359969 |
| 17 | 1056070674294 |
| 18 | 5320018479679 |
| 19 | 26799907726860 |
| 20 | 135006120168881 |
| 21 | 680101314855906 |
| 22 | 3426050596003631 |
| 23 | 17258932500172776 |