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 | 0 |
| 2 | 1 |
| 3 | 34 |
| 4 | 375 |
| 5 | 3149 |
| 6 | 24190 |
| 7 | 181265 |
| 8 | 1362669 |
| 9 | 10419024 |
| 10 | 81602489 |
| 11 | 657087105 |
| 12 | 5449808144 |
| 13 | 46591975883 |
| 14 | 410650926413 |
| 15 | 3730465450474 |
| 16 | 34912477523059 |
| 17 | 336408561147777 |
| 18 | 3335270965246766 |
| 19 | 33998967702498997 |
| 20 | 356088425256135353 |
| 21 | 3829087912372677696 |