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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 11 |
| 6 | 53 |
| 7 | 103 |
| 8 | 2119 |
| 9 | 16687 |
| 10 | 16481 |
| 11 | 1468457 |
| 12 | 16019531 |
| 13 | 63633137 |
| 14 | 2467007773 |
| 15 | 34361893981 |
| 16 | 15549624751 |
| 17 | 8178130767479 |
| 18 | 138547156531409 |
| 19 | 92079694567171 |
| 20 | 4282366656425369 |
| 21 | 72289643288657479 |
| 22 | 6563440628747948887 |
| 23 | 39299278806015611311 |