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 | 6 |
| 3 | 12 |
| 4 | 40 |
| 5 | 90 |
| 6 | 216 |
| 7 | 462 |
| 8 | 976 |
| 9 | 1980 |
| 10 | 3940 |
| 11 | 7678 |
| 12 | 14736 |
| 13 | 27898 |
| 14 | 52220 |
| 15 | 96780 |
| 16 | 177824 |
| 17 | 324258 |
| 18 | 587304 |
| 19 | 1057350 |
| 20 | 1893320 |
| 21 | 3373692 |
| 22 | 5984924 |
| 23 | 10574342 |
| 24 | 18613920 |
| 25 | 32654450 |
| 26 | 57106036 |
| 27 | 99576972 |
| 28 | 173166616 |
| 29 | 300385770 |
| 30 | 519849720 |