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 | 286 |
| 2 | 1758 |
| 3 | 10505 |
| 4 | 44366 |
| 5 | 189580 |
| 6 | 642272 |
| 7 | 2198077 |
| 8 | 6415866 |
| 9 | 18855400 |
| 10 | 49463034 |
| 11 | 130378965 |
| 12 | 316145840 |
| 13 | 769485458 |
| 14 | 1759764220 |
| 15 | 4037835608 |
| 16 | 8842012560 |
| 17 | 19423451542 |
| 18 | 41206754874 |
| 19 | 87691553223 |
| 20 | 181894892784 |
| 21 | 378439038413 |