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 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 34 |
| 6 | 90 |
| 7 | 243 |
| 8 | 660 |
| 9 | 1818 |
| 10 | 5045 |
| 11 | 14102 |
| 12 | 39639 |
| 13 | 111982 |
| 14 | 317533 |
| 15 | 903464 |
| 16 | 2577724 |
| 17 | 7372542 |
| 18 | 21130127 |
| 19 | 60672017 |
| 20 | 174492633 |
| 21 | 502568607 |
| 22 | 1449360241 |
| 23 | 4184719174 |
| 24 | 12095325486 |
| 25 | 34993693260 |
| 26 | 101332159421 |
| 27 | 293669741860 |
| 28 | 851722291650 |
| 29 | 2471948910379 |
| 30 | 6824540110584 |