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 | 16 |
| 3 | 104 |
| 4 | 752 |
| 5 | 5996 |
| 6 | 50512 |
| 7 | 444256 |
| 8 | 4027360 |
| 9 | 37383044 |
| 10 | 353486320 |
| 11 | 3393093696 |
| 12 | 32976302800 |
| 13 | 323839605124 |
| 14 | 3208549483216 |
| 15 | 32033691247528 |
| 16 | 321955764477936 |
| 17 | 3254812520854980 |
| 18 | 33075467402453872 |
| 19 | 337670437247448728 |
| 20 | 3461635652745799136 |
| 21 | 35620112071990294784 |