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 | 1 |
| 1 | 348 |
| 2 | 436 |
| 3 | 6018 |
| 4 | 5880 |
| 5 | -1 |
| 6 | 4612 |
| 7 | 26921 |
| 8 | 16166 |
| 9 | 81111 |
| 10 | -1 |
| 11 | 426260 |
| 12 | -1 |
| 13 | 181876 |
| 14 | 227180 |
| 15 | -1 |
| 16 | 12836 |
| 17 | 287388 |
| 18 | 2317 |
| 19 | -1 |
| 20 | -1 |
| 21 | 1128403 |
| 22 | 668927 |
| 23 | -1 |
| 24 | 5295 |
| 25 | -1 |
| 26 | -1 |
| 27 | 490118 |
| 28 | 2217967 |
| 29 | 1607226 |
| 30 | -1 |
| 31 | 1212183 |
| 32 | 100728 |
| 33 | -1 |
| 34 | -1 |
| 35 | -1 |
| 36 | -1 |
| 37 | 1191713 |
| 38 | 43475567 |
| 39 | 165965 |
| 40 | -1 |
| 41 | 2915491 |
| 42 | 361885 |
| 43 | 4159496 |
| 44 | 3398061 |
| 45 | -1 |
| 46 | 88930 |
| 47 | -1 |
| 48 | 10451327 |
| 49 | -1 |
| 50 | -1 |