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 | 120 |
| 2 | 276 |
| 3 | 1176 |
| 4 | 28920 |
| 5 | 126756 |
| 6 | 306936 |
| 7 | 1345620 |
| 8 | 33362196 |
| 9 | 146264856 |
| 10 | 354192420 |
| 11 | 1552832856 |
| 12 | 38499933816 |
| 13 | 168789505620 |
| 14 | 408737734296 |
| 15 | 1791967758756 |
| 16 | 44428890250020 |
| 17 | 194782943209176 |
| 18 | 471682991173716 |
| 19 | 2067929240760120 |
| 20 | 51270900848577816 |
| 21 | 224779347673872036 |