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 | 54 |
| 2 | 2917 |
| 3 | 157572 |
| 4 | 8511805 |
| 5 | 459795042 |
| 6 | 24837444073 |
| 7 | 1341681774984 |
| 8 | 72475653293209 |
| 9 | 3915026959608270 |
| 10 | 211483931472139789 |
| 11 | 11424047326455156876 |
| 12 | 617110039560050611093 |
| 13 | 33335366183569188155898 |
| 14 | 1800726883952296211029585 |
| 15 | 97272587099607564583753488 |