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 | 126 |
| 5 | 1512 |
| 6 | 9702 |
| 7 | 44352 |
| 8 | 162162 |
| 9 | 504504 |
| 10 | 1387386 |
| 11 | 3459456 |
| 12 | 7963956 |
| 13 | 17153136 |
| 14 | 34918884 |
| 15 | 67721472 |
| 16 | 125919612 |
| 17 | 225629712 |
| 18 | 391270572 |
| 19 | 658982016 |
| 20 | 1081142370 |
| 21 | 1732250520 |
| 22 | 2716483770 |
| 23 | 4177293120 |
| 24 | 6309453150 |
| 25 | 9374044680 |
| 26 | 13716915030 |
| 27 | 19791233280 |
| 28 | 28184836680 |