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 | 3 |
| 1 | 7 |
| 2 | 5 |
| 3 | 0 |
| 4 | 277 |
| 5 | 1109 |
| 6 | 0 |
| 7 | 17749 |
| 8 | 70997 |
| 9 | 0 |
| 10 | 1398037 |
| 11 | 5526869 |
| 12 | 0 |
| 13 | 72701269 |
| 14 | 357915989 |
| 15 | 0 |
| 16 | 5659514197 |
| 17 | 22902297941 |
| 18 | 0 |
| 19 | 297784399189 |
| 20 | 1465948394837 |
| 21 | 0 |
| 22 | 23456248042837 |
| 23 | 89426945725781 |
| 24 | 0 |
| 25 | 1430831131612501 |
| 26 | 6004798429418837 |
| 27 | 0 |