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 | 2 |
| 3 | 129 |
| 4 | 514 |
| 5 | 4194305 |
| 6 | 9218 |
| 7 | 470184984577 |
| 8 | 17179877378 |
| 9 | 609359740018689 |
| 10 | 4402341478402 |
| 11 | 100000000000000000000001 |
| 12 | 1125899907563522 |
| 13 | 137370551967459378662586974209 |
| 14 | 36845784908492735250434 |
| 15 | 9903520314283046597240029185 |