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 | 5 |
| 2 | 45 |
| 3 | 405 |
| 4 | 3645 |
| 5 | 32805 |
| 6 | 295245 |
| 7 | 2657205 |
| 8 | 23914845 |
| 9 | 215233605 |
| 10 | 1937102445 |
| 11 | 17433922005 |
| 12 | 156905298045 |
| 13 | 1412147682405 |
| 14 | 12709329141645 |
| 15 | 114383962274805 |
| 16 | 1029455660473245 |
| 17 | 9265100944259205 |
| 18 | 83385908498332845 |
| 19 | 750473176484995605 |
| 20 | 6754258588364960445 |
| 21 | 60788327295284644005 |