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 | 1 |
| 2 | 2731 |
| 3 | 398581 |
| 4 | 13421773 |
| 5 | 203450521 |
| 6 | 1865813431 |
| 7 | 12111126301 |
| 8 | 61083979321 |
| 9 | 254186582833 |
| 10 | 909090909091 |
| 11 | 2876892678661 |
| 12 | 8230246567621 |
| 13 | 21633936185161 |
| 14 | 52914318216943 |
| 15 | 121637191772461 |
| 16 | 264917625139441 |
| 17 | 550254335161441 |