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 | 20 |
| 2 | 225 |
| 3 | 3252 |
| 4 | 223271 |
| 5 | 297699 |
| 6 | 399233 |
| 7 | 715623 |
| 8 | 3263907 |
| 9 | 32347303 |
| 10 | 160720129 |
| 11 | 1153139393 |
| 12 | 72171972859 |
| 13 | 736728093411 |
| 14 | 3245576031137 |
| 15 | 11295052366467 |
| 16 | 310807934835791 |
| 17 | 1789205424940407 |
| 18 | 31745337977379983 |
| 19 | 1122916740775279751 |
| 20 | 7251536377635958081 |
| 21 | 151243563319717018007 |