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 | 13 |
| 3 | 72 |
| 4 | 464 |
| 5 | 2853 |
| 6 | 17617 |
| 7 | 108785 |
| 8 | 671452 |
| 9 | 4144996 |
| 10 | 25586605 |
| 11 | 157944449 |
| 12 | 974979853 |
| 13 | 6018479996 |
| 14 | 37151644524 |
| 15 | 229334423389 |
| 16 | 1415664871777 |
| 17 | 8738797243193 |
| 18 | 53943965676260 |
| 19 | 332992213004236 |
| 20 | 2055536935944305 |