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 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 129 |
| 5 | 3224 |
| 6 | 116065 |
| 7 | 5687184 |
| 8 | 363979777 |
| 9 | 29482361936 |
| 10 | 2948236193601 |
| 11 | 356736579425720 |
| 12 | 51370067437303681 |
| 13 | 8681541396904322088 |
| 14 | 1701582113793247129249 |
| 15 | 382855975603480604081024 |
| 16 | 98011129754491034644742145 |
| 17 | 28325216499047909012330479904 |
| 18 | 9177370145691522519995075488897 |