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) |
|---|---|
| 2 | 1 |
| 3 | 7 |
| 4 | 30 |
| 5 | 119 |
| 6 | 467 |
| 7 | 1820 |
| 8 | 7076 |
| 9 | 27493 |
| 10 | 106848 |
| 11 | 415538 |
| 12 | 1617504 |
| 13 | 6302416 |
| 14 | 24581249 |
| 15 | 95968478 |
| 16 | 375029576 |
| 17 | 1466881997 |
| 18 | 5742440324 |
| 19 | 22498218218 |
| 20 | 88212326756 |
| 21 | 346114729562 |
| 22 | 1358944775654 |
| 23 | 5338963361408 |
| 24 | 20987909276600 |