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 | 1 |
| 2 | 4 |
| 3 | 52 |
| 4 | 912 |
| 5 | 17992 |
| 6 | 377004 |
| 7 | 8189036 |
| 8 | 182127464 |
| 9 | 4118242896 |
| 10 | 94264009684 |
| 11 | 2177854717348 |
| 12 | 50687305553024 |
| 13 | 1186694487776152 |
| 14 | 27918432252733692 |
| 15 | 659490547066121820 |
| 16 | 15632281755808999768 |
| 17 | 371637556504994957728 |
| 18 | 8857868330404952584100 |
| 19 | 211598146901545394669844 |