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) |
|---|---|
| 4 | 1 |
| 5 | 10 |
| 6 | 65 |
| 7 | 350 |
| 8 | 1701 |
| 9 | 7770 |
| 10 | 34105 |
| 11 | 145750 |
| 12 | 611501 |
| 13 | 2532530 |
| 14 | 10391745 |
| 15 | 42355950 |
| 16 | 171798901 |
| 17 | 694337290 |
| 18 | 2798806985 |
| 19 | 11259666950 |
| 20 | 45232115901 |
| 21 | 181509070050 |
| 22 | 727778623825 |
| 23 | 2916342574750 |
| 24 | 11681056634501 |
| 25 | 46771289738810 |
| 26 | 187226356946265 |
| 27 | 749329038535350 |