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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 58 |
| 5 | 907 |
| 6 | 19046 |
| 7 | 496869 |
| 8 | 15578130 |
| 9 | 570573623 |
| 10 | 23929861102 |
| 11 | 1131235173433 |
| 12 | 59529368839898 |
| 13 | 3451899685313523 |
| 14 | 218712237867226182 |
| 15 | 15034642075916533997 |
| 16 | 1114519318895861250082 |
| 17 | 88631119148029975177327 |
| 18 | 7526795487859400166772958 |
| 19 | 679859967684397018073935617 |