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 | 1 |
| 5 | 11 |
| 6 | 96 |
| 7 | 785 |
| 8 | 6283 |
| 9 | 49987 |
| 10 | 397768 |
| 11 | 3174084 |
| 12 | 25426290 |
| 13 | 204538114 |
| 14 | 1652327820 |
| 15 | 13402442651 |
| 16 | 109129475455 |
| 17 | 891793354235 |
| 18 | 7312118010384 |
| 19 | 60141701374424 |
| 20 | 496095022537998 |
| 21 | 4103183675407098 |
| 22 | 34022136992384720 |