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 | 3 |
| 1 | 28 |
| 2 | 186 |
| 3 | 3458 |
| 4 | 21966 |
| 5 | 375816 |
| 6 | 2911272 |
| 7 | 45470096 |
| 8 | 340452396 |
| 9 | 6278429920 |
| 10 | 39543942612 |
| 11 | 706019328000 |
| 12 | 4708961513592 |
| 13 | 82162955169792 |
| 14 | 599236951715280 |
| 15 | 11195197038864384 |
| 16 | 68925937595777100 |
| 17 | 1179397832668228992 |
| 18 | 9136813499663186064 |
| 19 | 144079834776308121600 |