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 | 3 |
| 2 | 26 |
| 3 | 99 |
| 4 | 495 |
| 5 | 728 |
| 6 | 1215 |
| 7 | 6560 |
| 8 | 309824 |
| 9 | 1896128 |
| 10 | 1043199 |
| 11 | 15752960 |
| 12 | 178149375 |
| 13 | 399112191 |
| 14 | 4226550272 |
| 15 | 7219625984 |
| 16 | 45990608895 |
| 17 | 558743781375 |
| 18 | 1565795778560 |
| 19 | 28996228218879 |
| 20 | 63685431525375 |
| 21 | 45922887663615 |
| 22 | 1956754664980479 |
| 23 | 30987856352641023 |