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 | 9 |
| 4 | 78 |
| 5 | 750 |
| 6 | 8115 |
| 7 | 98343 |
| 8 | 1324204 |
| 9 | 19650060 |
| 10 | 318926745 |
| 11 | 5623615965 |
| 12 | 107093749818 |
| 13 | 2191142272410 |
| 14 | 47944109702671 |
| 15 | 1117341011896515 |
| 16 | 27633982917342360 |
| 17 | 722929036749464280 |
| 18 | 19946727355457792853 |
| 19 | 578926427416920550233 |
| 20 | 17632301590672398115270 |