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 | 19 |
| 3 | 173 |
| 4 | 1881 |
| 5 | 22655 |
| 6 | 291775 |
| 7 | 3940725 |
| 8 | 55149025 |
| 9 | 793387235 |
| 10 | 11668476579 |
| 11 | 174735112997 |
| 12 | 2656296912361 |
| 13 | 40897718776647 |
| 14 | 636588467802679 |
| 15 | 10002872642155085 |
| 16 | 158483629611962025 |
| 17 | 2529389028336106475 |
| 18 | 40631849127696017275 |
| 19 | 656509442594976984405 |
| 20 | 10663184061320964941761 |