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 | 126 |
| 2 | 534 |
| 3 | 2262 |
| 4 | 9582 |
| 5 | 40590 |
| 6 | 171942 |
| 7 | 728358 |
| 8 | 3085374 |
| 9 | 13069854 |
| 10 | 55364790 |
| 11 | 234529014 |
| 12 | 993480846 |
| 13 | 4208452398 |
| 14 | 17827290438 |
| 15 | 75517614150 |
| 16 | 319897747038 |
| 17 | 1355108602302 |
| 18 | 5740332156246 |
| 19 | 24316437227286 |
| 20 | 103006081065390 |