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 | 4 |
| 2 | 31 |
| 3 | 358 |
| 4 | 5509 |
| 5 | 106096 |
| 6 | 2456299 |
| 7 | 66471826 |
| 8 | 2059640713 |
| 9 | 71920704124 |
| 10 | 2794938616471 |
| 11 | 119653108240414 |
| 12 | 5595650767265101 |
| 13 | 283841520215780008 |
| 14 | 15523069639558351459 |
| 15 | 910529206043204428426 |
| 16 | 57023540590242398853649 |
| 17 | 3797750659849704886903156 |
| 18 | 268025698704886063968108943 |