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 | 5 |
| 3 | 4 |
| 4 | 25 |
| 5 | 40 |
| 6 | 141 |
| 7 | 300 |
| 8 | 865 |
| 9 | 2064 |
| 10 | 5525 |
| 11 | 13780 |
| 12 | 35881 |
| 13 | 91000 |
| 14 | 234525 |
| 15 | 598524 |
| 16 | 1536625 |
| 17 | 3930720 |
| 18 | 10077221 |
| 19 | 25800100 |
| 20 | 66108985 |
| 21 | 169309384 |
| 22 | 433745325 |
| 23 | 1110982860 |
| 24 | 2845964161 |
| 25 | 7289895600 |
| 26 | 18673752245 |
| 27 | 47833334644 |
| 28 | 122528343625 |
| 29 | 313861682200 |
| 30 | 803975056701 |