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 | 6 |
| 3 | 24 |
| 4 | 181 |
| 5 | 941 |
| 6 | 4662 |
| 7 | 23691 |
| 8 | 119271 |
| 9 | 603760 |
| 10 | 3050402 |
| 11 | 15428576 |
| 12 | 78004550 |
| 13 | 394462578 |
| 14 | 1994595585 |
| 15 | 10086050889 |
| 16 | 51001111356 |
| 17 | 257894037378 |
| 18 | 1304071170194 |
| 19 | 6594196094078 |
| 20 | 33344335235915 |
| 21 | 168609627579175 |
| 22 | 852594638783225 |
| 23 | 4311246376730011 |