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 | 0 |
| 3 | 0 |
| 4 | 228 |
| 5 | 3850 |
| 6 | 27225 |
| 7 | 122892 |
| 8 | 423152 |
| 9 | 1213380 |
| 10 | 3046025 |
| 11 | 6907890 |
| 12 | 14454972 |
| 13 | 28330822 |
| 14 | 52586065 |
| 15 | 93218400 |
| 16 | 158854080 |
| 17 | 261593552 |
| 18 | 418045617 |
| 19 | 650576150 |
| 20 | 988799100 |
| 21 | 1471339170 |
| 22 | 2147897257 |
| 23 | 3081651412 |
| 24 | 4352027760 |
| 25 | 6057877500 |
| 26 | 8321097785 |
| 27 | 11290735962 |