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 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 56 |
| 6 | 289 |
| 7 | 1604 |
| 8 | 9415 |
| 9 | 57801 |
| 10 | 368269 |
| 11 | 2421115 |
| 12 | 16352401 |
| 13 | 113075441 |
| 14 | 798316997 |
| 15 | 5741446395 |
| 16 | 41984708298 |
| 17 | 311673028845 |
| 18 | 2345644392051 |
| 19 | 17876342623580 |
| 20 | 137820598360123 |
| 21 | 1073961913716521 |
| 22 | 8452182814380104 |
| 23 | 67136452766364121 |
| 24 | 537890721293399309 |