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 | 4 |
| 2 | 48 |
| 3 | 1040 |
| 4 | 7840 |
| 5 | 118096 |
| 6 | 321776 |
| 7 | 1609152 |
| 8 | 3136368 |
| 9 | 9869024 |
| 10 | 39654832 |
| 11 | 59166848 |
| 12 | 171048336 |
| 13 | 316673504 |
| 14 | 421424080 |
| 15 | 718614208 |
| 16 | 1477623888 |
| 17 | 2812035344 |
| 18 | 3434691376 |
| 19 | 6030558512 |
| 20 | 8540018592 |
| 21 | 10088948064 |
| 22 | 16205829952 |
| 23 | 21796024432 |