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 | 1 |
| 2 | 4 |
| 3 | 29 |
| 4 | 263 |
| 5 | 2724 |
| 6 | 30554 |
| 7 | 361677 |
| 8 | 4454273 |
| 9 | 56546511 |
| 10 | 735298671 |
| 11 | 9749613914 |
| 12 | 131377492010 |
| 13 | 1794546880363 |
| 14 | 24798396567242 |
| 15 | 346130144084641 |
| 16 | 4873560434459530 |
| 17 | 69149450121948083 |
| 18 | 987844051312409668 |
| 19 | 14198028410251734447 |
| 20 | 205181815270346718199 |