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 | 40 |
| 3 | 460 |
| 4 | 7220 |
| 5 | 148276 |
| 6 | 3831760 |
| 7 | 120333680 |
| 8 | 4460572870 |
| 9 | 190679906990 |
| 10 | 9230084185456 |
| 11 | 498734395394840 |
| 12 | 29740372199558420 |
| 13 | 1939241402832412180 |
| 14 | 137222625361036807760 |
| 15 | 10470376552560151801616 |
| 16 | 856818090423771231257245 |