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 | 4 |
| 2 | 22 |
| 3 | 184 |
| 4 | 2128 |
| 5 | 31288 |
| 6 | 556168 |
| 7 | 11578648 |
| 8 | 276118168 |
| 9 | 7418685208 |
| 10 | 221695696408 |
| 11 | 7292837066008 |
| 12 | 261853926371608 |
| 13 | 10189736409290008 |
| 14 | 427160800691862808 |
| 15 | 19190858693407638808 |
| 16 | 919848357543764886808 |
| 17 | 46853380798911984534808 |
| 18 | 2527264132632795845526808 |