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 | 1 |
| 1 | 40 |
| 2 | 540 |
| 3 | 4200 |
| 4 | 23100 |
| 5 | 99792 |
| 6 | 360360 |
| 7 | 1132560 |
| 8 | 3185325 |
| 9 | 8179600 |
| 10 | 19467448 |
| 11 | 43439760 |
| 12 | 91706160 |
| 13 | 184497600 |
| 14 | 355816800 |
| 15 | 661028544 |
| 16 | 1187785665 |
| 17 | 2071432440 |
| 18 | 3516320500 |
| 19 | 5824819000 |
| 20 | 9436206780 |
| 21 | 14978106000 |
| 22 | 23333661000 |
| 23 | 35728290000 |
| 24 | 53840548125 |
| 25 | 79942445856 |