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 | 0 |
| 1 | 1 |
| 2 | 18 |
| 3 | 291 |
| 4 | 4660 |
| 5 | 74565 |
| 6 | 1193046 |
| 7 | 19088743 |
| 8 | 305419896 |
| 9 | 4886718345 |
| 10 | 78187493530 |
| 11 | 1250999896491 |
| 12 | 20015998343868 |
| 13 | 320255973501901 |
| 14 | 5124095576030430 |
| 15 | 81985529216486895 |
| 16 | 1311768467463790336 |
| 17 | 20988295479420645393 |
| 18 | 335812727670730326306 |
| 19 | 5373003642731685220915 |