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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 19 |
| 4 | 83 |
| 5 | 391 |
| 6 | 1663 |
| 7 | 7739 |
| 8 | 33812 |
| 9 | 153575 |
| 10 | 677901 |
| 11 | 3075879 |
| 12 | 13586581 |
| 13 | 61458267 |
| 14 | 272367077 |
| 15 | 1228519987 |
| 16 | 5456053443 |
| 17 | 24547516939 |
| 18 | 109153816505 |
| 19 | 490067180301 |
| 20 | 2180061001275 |
| 21 | 9772927018285 |
| 22 | 43467641569472 |