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 | 18 |
| 2 | 251 |
| 3 | 3325 |
| 4 | 44524 |
| 5 | 617624 |
| 6 | 8969148 |
| 7 | 136954044 |
| 8 | 2201931576 |
| 9 | 37272482280 |
| 10 | 663644774880 |
| 11 | 12413008539360 |
| 12 | 243533741849280 |
| 13 | 5003753991174720 |
| 14 | 107497490419296000 |
| 15 | 2410964056571616000 |
| 16 | 56366432074677312000 |
| 17 | 1371711629236971456000 |
| 18 | 34699437370290760704000 |