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 | 2 |
| 2 | 11 |
| 3 | 66 |
| 4 | 470 |
| 5 | 3997 |
| 6 | 40079 |
| 7 | 466448 |
| 8 | 6208551 |
| 9 | 93297013 |
| 10 | 1565360082 |
| 11 | 29047075343 |
| 12 | 591275224311 |
| 13 | 13110484254998 |
| 14 | 314726620750589 |
| 15 | 8135993235767295 |
| 16 | 225426087495479680 |
| 17 | 6666553071325468948 |
| 18 | 209645759506867904384 |
| 19 | 6987310422457948266944 |
| 20 | 246075579251657940919613 |