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 | 77 |
| 3 | 1120 |
| 4 | 17199 |
| 5 | 272272 |
| 6 | 4395118 |
| 7 | 71916768 |
| 8 | 1188576675 |
| 9 | 19794795118 |
| 10 | 331670995656 |
| 11 | 5584693695280 |
| 12 | 94418718611490 |
| 13 | 1601780734932840 |
| 14 | 27253077978559384 |
| 15 | 464859662065426880 |
| 16 | 7946606112855555915 |
| 17 | 136106890528701061242 |
| 18 | 2335187812028912966125 |