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 | 6 |
| 1 | 21 |
| 2 | 291 |
| 3 | 56451 |
| 4 | 2124476931 |
| 5 | 3008934820234119171 |
| 6 | 6035792501611554034238453484153151491 |
| 7 | 24287194081673507672666338605180770497437885188248737771493963111463682051 |