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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 10 |
| 4 | 87 |
| 5 | 1046 |
| 6 | 15395 |
| 7 | 269060 |
| 8 | 5440463 |
| 9 | 124902874 |
| 10 | 3208994379 |
| 11 | 91208536112 |
| 12 | 2841279322871 |
| 13 | 96258245162678 |
| 14 | 3523457725743059 |
| 15 | 138573785311560916 |
| 16 | 5827414570508386335 |
| 17 | 260928229315498155314 |
| 18 | 12393729720071855683739 |
| 19 | 622422708333615857463608 |