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 | 3 |
| 2 | 14 |
| 3 | 78 |
| 4 | 416 |
| 5 | 2228 |
| 6 | 11912 |
| 7 | 63688 |
| 8 | 340480 |
| 9 | 1820208 |
| 10 | 9730784 |
| 11 | 52020448 |
| 12 | 278099456 |
| 13 | 1486709568 |
| 14 | 7947894912 |
| 15 | 42489154688 |
| 16 | 227145461760 |
| 17 | 1214311301888 |
| 18 | 6491663650304 |
| 19 | 34704195603968 |
| 20 | 185527355908096 |
| 21 | 991822435038208 |