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 | 0 |
| 2 | 3 |
| 3 | 13 |
| 4 | 17 |
| 5 | 781 |
| 6 | 31 |
| 7 | 137257 |
| 8 | 4097 |
| 9 | 532171 |
| 10 | 9091 |
| 11 | 28531167061 |
| 12 | 20593 |
| 13 | 25239592216021 |
| 14 | 7027567 |
| 15 | 2392743361 |
| 16 | 4294967297 |
| 17 | 51702516367896047761 |
| 18 | 34006393 |
| 19 | 109912203092239643840221 |
| 20 | 25536159601 |
| 21 | 7006306553612521 |
| 22 | 25405143539623 |
| 23 | 949112181811268728834319677753 |