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 | 4 |
| 3 | 17 |
| 4 | 73 |
| 5 | 319 |
| 6 | 1423 |
| 7 | 6499 |
| 8 | 30374 |
| 9 | 145302 |
| 10 | 711177 |
| 11 | 3559690 |
| 12 | 18212192 |
| 13 | 95193547 |
| 14 | 508083746 |
| 15 | 2767835600 |
| 16 | 15382476029 |
| 17 | 87177582535 |
| 18 | 503610832756 |
| 19 | 2964300557548 |
| 20 | 17771210411578 |
| 21 | 108471258414870 |
| 22 | 673836620069035 |
| 23 | 4258727230198033 |
| 24 | 27373904651169023 |
| 25 | 178885471934461869 |