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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 18 |
| 5 | 59 |
| 6 | 199 |
| 7 | 693 |
| 8 | 2465 |
| 9 | 8937 |
| 10 | 32880 |
| 11 | 122513 |
| 12 | 461331 |
| 13 | 1753037 |
| 14 | 6713758 |
| 15 | 25888515 |
| 16 | 100427611 |
| 17 | 391657635 |
| 18 | 1534674930 |
| 19 | 6039078032 |
| 20 | 23855475724 |
| 21 | 94561195899 |
| 22 | 376019415794 |
| 23 | 1499554893338 |
| 24 | 5996061250461 |
| 25 | 24034238674758 |
| 26 | 96554979145357 |
| 27 | 388711331661818 |
| 28 | 1567919554600690 |