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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 19 |
| 5 | 69 |
| 6 | 249 |
| 7 | 1025 |
| 8 | 4833 |
| 9 | 21481 |
| 10 | 126517 |
| 11 | 615669 |
| 12 | 4161321 |
| 13 | 22894537 |
| 14 | 163938841 |
| 15 | 1016069027 |
| 16 | 8491341479 |
| 17 | 58444280449 |
| 18 | 508568676159 |
| 19 | 3894634611571 |
| 20 | 33778806941777 |
| 21 | 290707450961639 |
| 22 | 2713715752910365 |
| 23 | 26549031384321585 |
| 24 | 233708327564162305 |
| 25 | 2519255296395164039 |
| 26 | 24379835547221372041 |