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 | 6 |
| 2 | 29 |
| 3 | 146 |
| 4 | 729 |
| 5 | 3646 |
| 6 | 18229 |
| 7 | 91146 |
| 8 | 455729 |
| 9 | 2278646 |
| 10 | 11393229 |
| 11 | 56966146 |
| 12 | 284830729 |
| 13 | 1424153646 |
| 14 | 7120768229 |
| 15 | 35603841146 |
| 16 | 178019205729 |
| 17 | 890096028646 |
| 18 | 4450480143229 |
| 19 | 22252400716146 |
| 20 | 111262003580729 |
| 21 | 556310017903646 |