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 | 6 |
| 2 | 45 |
| 3 | 432 |
| 4 | 5265 |
| 5 | 79218 |
| 6 | 1426653 |
| 7 | 29961900 |
| 8 | 719092161 |
| 9 | 19415508030 |
| 10 | 582465299949 |
| 11 | 19221355075464 |
| 12 | 691968783248145 |
| 13 | 26986782548271978 |
| 14 | 1133444867032206045 |
| 15 | 51005019016463620932 |
| 16 | 2448240912790296851457 |