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 | 5 |
| 3 | 23 |
| 4 | 165 |
| 5 | 1328 |
| 6 | 13193 |
| 7 | 145076 |
| 8 | 1774515 |
| 9 | 23600723 |
| 10 | 338704176 |
| 11 | 5202002092 |
| 12 | 85007211518 |
| 13 | 1470699469052 |
| 14 | 26828468813710 |
| 15 | 514213843983674 |
| 16 | 10323889080831256 |
| 17 | 216536421271101354 |
| 18 | 4733415248988274281 |
| 19 | 107609706100197846274 |
| 20 | 2539397701858619916499 |