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 | 29 |
| 3 | 139 |
| 4 | 666 |
| 5 | 3191 |
| 6 | 15289 |
| 7 | 73254 |
| 8 | 350981 |
| 9 | 1681651 |
| 10 | 8057274 |
| 11 | 38604719 |
| 12 | 184966321 |
| 13 | 886226886 |
| 14 | 4246168109 |
| 15 | 20344613659 |
| 16 | 97476900186 |
| 17 | 467039887271 |
| 18 | 2237722536169 |
| 19 | 10721572793574 |
| 20 | 51370141431701 |
| 21 | 246129134364931 |
| 22 | 1179275530392954 |
| 23 | 5650248517599839 |