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 | 8 |
| 3 | 58 |
| 4 | 408 |
| 5 | 2831 |
| 6 | 19496 |
| 7 | 133638 |
| 8 | 913200 |
| 9 | 6226591 |
| 10 | 42387168 |
| 11 | 288194424 |
| 12 | 1957583712 |
| 13 | 13286865060 |
| 14 | 90126841064 |
| 15 | 611029568078 |
| 16 | 4140789069408 |
| 17 | 28050809681679 |
| 18 | 189964288098632 |
| 19 | 1286119453570746 |
| 20 | 8705397371980728 |
| 21 | 58912358137385559 |
| 22 | 398607288093924192 |
| 23 | 2696583955707785256 |