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 | 2 |
| 2 | 15 |
| 3 | 1001 |
| 4 | 215441 |
| 5 | 95041567 |
| 6 | 66238993967 |
| 7 | 63009974049301 |
| 8 | 87796770491685553 |
| 9 | 173955570033393401009 |
| 10 | 421385360593324054690769 |
| 11 | 1172248885422611971256631487 |
| 12 | 5253333091597988325086927419397 |
| 13 | 21476254926032216698855019795863013 |