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 | 4 |
| 2 | 14 |
| 3 | 51 |
| 4 | 216 |
| 5 | 1095 |
| 6 | 6588 |
| 7 | 46137 |
| 8 | 369120 |
| 9 | 3322107 |
| 10 | 33221100 |
| 11 | 365432133 |
| 12 | 4385185632 |
| 13 | 57007413255 |
| 14 | 798103785612 |
| 15 | 11971556784225 |
| 16 | 191544908547648 |
| 17 | 3256263445310067 |
| 18 | 58612742015581260 |
| 19 | 1113642098296043997 |