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 | 6 |
| 3 | 47 |
| 4 | 424 |
| 5 | 4159 |
| 6 | 43097 |
| 7 | 464197 |
| 8 | 5145475 |
| 9 | 58313310 |
| 10 | 672598269 |
| 11 | 7869856070 |
| 12 | 93183973405 |
| 13 | 1114471042413 |
| 14 | 13443614108307 |
| 15 | 163372291277764 |
| 16 | 1998239045199623 |
| 17 | 24580340878055298 |
| 18 | 303893356012560280 |
| 19 | 3774099648814193998 |
| 20 | 47061518776483143441 |