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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 10 |
| 7 | 34 |
| 8 | 158 |
| 9 | 804 |
| 10 | 4876 |
| 11 | 35516 |
| 12 | 319719 |
| 13 | 3636064 |
| 14 | 53349918 |
| 15 | 1025758444 |
| 16 | 26132964903 |
| 17 | 888605372756 |
| 18 | 40526634099476 |
| 19 | 2487361532245964 |
| 20 | 205991405080129554 |
| 21 | 23065538883807036798 |
| 22 | 3498567662956243132910 |