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 | 1 |
| 2 | 5 |
| 3 | 29 |
| 4 | 125 |
| 5 | 2045 |
| 6 | 8189 |
| 7 | 131069 |
| 8 | 524285 |
| 9 | 8388605 |
| 10 | 536870909 |
| 11 | 2147483645 |
| 12 | 137438953469 |
| 13 | 2199023255549 |
| 14 | 8796093022205 |
| 15 | 140737488355325 |
| 16 | 9007199254740989 |
| 17 | 576460752303423485 |
| 18 | 2305843009213693949 |
| 19 | 147573952589676412925 |
| 20 | 2361183241434822606845 |