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 | 1 |
| 2 | 7 |
| 3 | 61 |
| 4 | 649 |
| 5 | 8245 |
| 6 | 122215 |
| 7 | 2069425 |
| 8 | 39328465 |
| 9 | 827226505 |
| 10 | 19047582055 |
| 11 | 475956135205 |
| 12 | 12815133759385 |
| 13 | 369605936607805 |
| 14 | 11361372997850695 |
| 15 | 370609338222772825 |
| 16 | 12780705695068446625 |
| 17 | 464412124831585889425 |
| 18 | 17729002673226394402375 |
| 19 | 709180766131239680070925 |