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 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 22 |
| 4 | 100 |
| 5 | 482 |
| 6 | 2475 |
| 7 | 13527 |
| 8 | 78476 |
| 9 | 481687 |
| 10 | 3117962 |
| 11 | 21218851 |
| 12 | 151387882 |
| 13 | 1129430737 |
| 14 | 8790433999 |
| 15 | 71222812912 |
| 16 | 599577147056 |
| 17 | 5235054113412 |
| 18 | 47331036294905 |
| 19 | 442462325254995 |
| 20 | 4270909302907430 |
| 21 | 42514043248222709 |
| 22 | 435920900603529954 |
| 23 | 4599155199953703373 |