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 | 3 |
| 3 | 11 |
| 4 | 51 |
| 5 | 295 |
| 6 | 2055 |
| 7 | 16715 |
| 8 | 155355 |
| 9 | 1624255 |
| 10 | 18868575 |
| 11 | 241112675 |
| 12 | 3361168275 |
| 13 | 50760093175 |
| 14 | 825541973175 |
| 15 | 14385306834875 |
| 16 | 267379330468875 |
| 17 | 5280383597275375 |
| 18 | 110414649582951375 |
| 19 | 2437075699774353875 |
| 20 | 56622329782817431875 |
| 21 | 1381324610464997374375 |
| 22 | 35302637257323023454375 |