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 | 0 |
| 1 | 3 |
| 2 | 12 |
| 3 | 51 |
| 4 | 192 |
| 5 | 675 |
| 6 | 2358 |
| 7 | 8043 |
| 8 | 26736 |
| 9 | 88659 |
| 10 | 290910 |
| 11 | 941985 |
| 12 | 3046068 |
| 13 | 9791613 |
| 14 | 31221414 |
| 15 | 99466515 |
| 16 | 315677664 |
| 17 | 996398883 |
| 18 | 3143147598 |
| 19 | 9888728505 |
| 20 | 30988353300 |
| 21 | 97066250379 |
| 22 | 303448558578 |
| 23 | 945804661377 |
| 24 | 2946961001304 |
| 25 | 9168357598425 |
| 26 | 28456994858058 |
| 27 | 88302639334743 |