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 | 0 |
| 1 | 5 |
| 2 | 140 |
| 3 | 6080 |
| 4 | 186620 |
| 5 | 3504380 |
| 6 | 43599605 |
| 7 | 392515340 |
| 8 | 2738219580 |
| 9 | 15571795365 |
| 10 | 74962059260 |
| 11 | 314303754380 |
| 12 | 1173239918240 |
| 13 | 3966582090380 |
| 14 | 12313551210485 |
| 15 | 35488970536640 |
| 16 | 95826048090080 |
| 17 | 244240228906965 |
| 18 | 591327577603980 |
| 19 | 1367189227172480 |
| 20 | 3032433080571020 |