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 | 41 |
| 3 | 281 |
| 4 | 1926 |
| 5 | 13201 |
| 6 | 90481 |
| 7 | 620166 |
| 8 | 4250681 |
| 9 | 29134601 |
| 10 | 199691526 |
| 11 | 1368706081 |
| 12 | 9381251041 |
| 13 | 64300051206 |
| 14 | 440719107401 |
| 15 | 3020733700601 |
| 16 | 20704416796806 |
| 17 | 141910183877041 |
| 18 | 972666870342481 |
| 19 | 6666757908520326 |
| 20 | 45694638489299801 |
| 21 | 313195711516578281 |