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 | 31 |
| 4 | 291 |
| 5 | 3092 |
| 6 | 35839 |
| 7 | 441925 |
| 8 | 5721008 |
| 9 | 77009425 |
| 10 | 1071034612 |
| 11 | 15319883964 |
| 12 | 224628789200 |
| 13 | 3368096726910 |
| 14 | 51552652046550 |
| 15 | 804490751228163 |
| 16 | 12788591015038781 |
| 17 | 206977224029107906 |
| 18 | 3409582505289727239 |
| 19 | 57165456138722305360 |