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) |
|---|---|
| 3 | 7 |
| 4 | 234 |
| 5 | 5390 |
| 6 | 113126 |
| 7 | 2371845 |
| 8 | 51607716 |
| 9 | 1185214452 |
| 10 | 28937407212 |
| 11 | 752882360571 |
| 12 | 20870819679150 |
| 13 | 615571317411570 |
| 14 | 19277508315195090 |
| 15 | 639508594242409065 |
| 16 | 22419339547774938120 |
| 17 | 828617069130919072200 |
| 18 | 32214653364317860157400 |
| 19 | 1314580813236368248272975 |
| 20 | 56192348229571762396268850 |