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 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 63 |
| 5 | 729 |
| 6 | 10113 |
| 7 | 161935 |
| 8 | 2923135 |
| 9 | 58547761 |
| 10 | 1286468225 |
| 11 | 30747331223 |
| 12 | 793992877247 |
| 13 | 22031281255689 |
| 14 | 653827064820993 |
| 15 | 20670172958564127 |
| 16 | 693662602935500031 |
| 17 | 24632233419065156193 |
| 18 | 922938914156271368961 |