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 | 13 |
| 2 | 505 |
| 3 | 24691 |
| 4 | 1337961 |
| 5 | 76869013 |
| 6 | 4586370139 |
| 7 | 280973874215 |
| 8 | 17552736006121 |
| 9 | 1113134497824901 |
| 10 | 71437216036404505 |
| 11 | 4629194489296980715 |
| 12 | 302391678415222922475 |
| 13 | 19886936616891022422159 |
| 14 | 1315438146193644502479255 |
| 15 | 87445220568000089973356191 |
| 16 | 5838332204000163260729138153 |