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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 27 |
| 3 | 325 |
| 4 | 4488 |
| 5 | 67158 |
| 6 | 1059380 |
| 7 | 17346582 |
| 8 | 292046040 |
| 9 | 5023824887 |
| 10 | 87915626370 |
| 11 | 1560176040519 |
| 12 | 28011228029512 |
| 13 | 507874087572600 |
| 14 | 9286024289123268 |
| 15 | 171026036066072924 |
| 16 | 3169969149156895800 |
| 17 | 59085490354010508600 |
| 18 | 1106795192170066119435 |