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 | 273 |
| 2 | 1820 |
| 3 | 7140 |
| 4 | 21420 |
| 5 | 54264 |
| 6 | 122094 |
| 7 | 251370 |
| 8 | 482790 |
| 9 | 876645 |
| 10 | 1519518 |
| 11 | 2532530 |
| 12 | 4081350 |
| 13 | 6388200 |
| 14 | 9746100 |
| 15 | 14535612 |
| 16 | 21244356 |
| 17 | 30489585 |
| 18 | 43044120 |
| 19 | 59865960 |
| 20 | 82131896 |
| 21 | 111275472 |
| 22 | 149029650 |
| 23 | 197474550 |
| 24 | 259090650 |
| 25 | 336817845 |
| 26 | 434120778 |
| 27 | 555060870 |
| 28 | 704375490 |
| 29 | 887564720 |
| 30 | 1110986184 |