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 | 238 |
| 4 | 1316 |
| 5 | 7196 |
| 6 | 39158 |
| 7 | 212738 |
| 8 | 1155889 |
| 9 | 6287015 |
| 10 | 34249404 |
| 11 | 186920468 |
| 12 | 1022134288 |
| 13 | 5600420336 |
| 14 | 30745867316 |
| 15 | 169116129308 |
| 16 | 931937277257 |
| 17 | 5144687596447 |
| 18 | 28449040406262 |
| 19 | 157571572143538 |
| 20 | 874089046798212 |