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) |
|---|---|
| 1 | 2 |
| 2 | 84 |
| 3 | 1962 |
| 4 | 32130 |
| 5 | 406800 |
| 6 | 4208610 |
| 7 | 36881420 |
| 8 | 280819260 |
| 9 | 1893408750 |
| 10 | 11472968760 |
| 11 | 63221641758 |
| 12 | 319917948246 |
| 13 | 1498750896708 |
| 14 | 6545498596110 |
| 15 | 26808012135000 |
| 16 | 103501142484360 |
| 17 | 378407481456870 |
| 18 | 1315394383751460 |
| 19 | 4363052456797550 |
| 20 | 13853429338548630 |