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 | 3 |
| 3 | 7 |
| 4 | 23 |
| 5 | 70 |
| 6 | 242 |
| 7 | 832 |
| 8 | 2983 |
| 9 | 10759 |
| 10 | 39482 |
| 11 | 145892 |
| 12 | 543877 |
| 13 | 2038831 |
| 14 | 7685211 |
| 15 | 29092055 |
| 16 | 110554267 |
| 17 | 421495147 |
| 18 | 1611676767 |