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 | 6 |
| 2 | 135 |
| 3 | 4140 |
| 4 | 146475 |
| 5 | 5629338 |
| 6 | 228355281 |
| 7 | 9622693080 |
| 8 | 417122726490 |
| 9 | 18480617374050 |
| 10 | 833136935399208 |
| 11 | 38094723501749460 |
| 12 | 1762459398803643930 |
| 13 | 82353342267057244950 |
| 14 | 3880848811889775489300 |
| 15 | 184228926273804535479216 |
| 16 | 8801795826996054546077865 |
| 17 | 422898288144162288398536860 |