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 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 16 |
| 9 | 136 |
| 10 | 816 |
| 11 | 3876 |
| 12 | 15504 |
| 13 | 54264 |
| 14 | 170544 |
| 15 | 490315 |
| 16 | 1307536 |
| 17 | 3269288 |
| 18 | 7732144 |
| 19 | 17436220 |
| 20 | 37819152 |
| 21 | 79883544 |
| 22 | 167737776 |
| 23 | 362063944 |
| 24 | 839161648 |
| 25 | 2158258904 |
| 26 | 6136548496 |
| 27 | 18586871324 |
| 28 | 57486027952 |
| 29 | 176258492200 |
| 30 | 527387147664 |
| 31 | 1529591016109 |