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 | 0 |
| 3 | 1 |
| 4 | 5 |
| 5 | 16 |
| 6 | 52 |
| 7 | 274 |
| 8 | 1990 |
| 9 | 14354 |
| 10 | 99704 |
| 11 | 730225 |
| 12 | 6061013 |
| 13 | 56151330 |
| 14 | 551040830 |
| 15 | 5597109717 |
| 16 | 59324775741 |
| 17 | 664973687438 |
| 18 | 7891158217876 |
| 19 | 98253448977890 |
| 20 | 1273082291906394 |
| 21 | 17124091446383666 |
| 22 | 239333235895599762 |
| 23 | 3476600533730954761 |
| 24 | 52394273274018321421 |