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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 8 |
| 7 | 59 |
| 8 | 427 |
| 9 | 2768 |
| 10 | 16461 |
| 11 | 90111 |
| 12 | 460699 |
| 13 | 2222549 |
| 14 | 10216607 |
| 15 | 45076266 |
| 16 | 192059940 |
| 17 | 794088479 |
| 18 | 3198709835 |
| 19 | 12593964702 |
| 20 | 48596474890 |
| 21 | 184195614359 |
| 22 | 687087962550 |
| 23 | 2526421534903 |