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 | 16 |
| 4 | 429 |
| 5 | 7039 |
| 6 | 92966 |
| 7 | 1103888 |
| 8 | 12364826 |
| 9 | 133702610 |
| 10 | 1413227318 |
| 11 | 14709861824 |
| 12 | 151469044739 |
| 13 | 1547593008310 |
| 14 | 15721130285808 |
| 15 | 159006397271949 |
| 16 | 1602820838558101 |
| 17 | 16114386617828822 |
| 18 | 161673560523193369 |
| 19 | 1619352576852638084 |
| 20 | 16197963371445222701 |