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 | 15 |
| 4 | 264 |
| 5 | 1700 |
| 6 | 6900 |
| 7 | 21315 |
| 8 | 54880 |
| 9 | 123984 |
| 10 | 253800 |
| 11 | 480975 |
| 12 | 856680 |
| 13 | 1450020 |
| 14 | 2351804 |
| 15 | 3678675 |
| 16 | 5577600 |
| 17 | 8230720 |
| 18 | 11860560 |
| 19 | 16735599 |
| 20 | 23176200 |
| 21 | 31560900 |
| 22 | 42333060 |
| 23 | 56007875 |
| 24 | 73179744 |
| 25 | 94530000 |
| 26 | 120835000 |
| 27 | 152974575 |
| 28 | 191940840 |
| 29 | 238847364 |
| 30 | 294938700 |