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 | 7 |
| 3 | 75 |
| 4 | 989 |
| 5 | 14822 |
| 6 | 242833 |
| 7 | 4253818 |
| 8 | 78573475 |
| 9 | 1516124048 |
| 10 | 30358711661 |
| 11 | 627789264431 |
| 12 | 13357722853019 |
| 13 | 291611321803145 |
| 14 | 6517101781199460 |
| 15 | 148833150175812360 |
| 16 | 3468184751644757228 |
| 17 | 82363850033966966043 |
| 18 | 1991430772785525516280 |
| 19 | 48980124394583747435367 |