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 | 515 |
| 4 | 10810 |
| 5 | 376175 |
| 6 | 22099885 |
| 7 | 2231417165 |
| 8 | 393643922005 |
| 9 | 123097221805100 |
| 10 | 69087264010363930 |
| 11 | 70321483026073531730 |
| 12 | 130954011392485408662370 |
| 13 | 449450774746306949114288795 |