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 | 21 |
| 2 | 301 |
| 3 | 4088 |
| 4 | 55354 |
| 5 | 756059 |
| 6 | 10442117 |
| 7 | 145803900 |
| 8 | 2056351566 |
| 9 | 29262470042 |
| 10 | 419730456306 |
| 11 | 6062949606496 |
| 12 | 88127311401876 |
| 13 | 1288120149337735 |
| 14 | 18922077118169717 |
| 15 | 279209456350438708 |
| 16 | 4136682188907493702 |
| 17 | 61513664658938124486 |
| 18 | 917795824360157700870 |