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 | 25 |
| 3 | 265 |
| 4 | 2161 |
| 5 | 16081 |
| 6 | 115465 |
| 7 | 816985 |
| 8 | 5745121 |
| 9 | 40294561 |
| 10 | 282298105 |
| 11 | 1976795305 |
| 12 | 13839692881 |
| 13 | 96884227441 |
| 14 | 678208723945 |
| 15 | 4747518463225 |
| 16 | 33232801429441 |
| 17 | 232630126566721 |
| 18 | 1628412435648985 |
| 19 | 11398891698588745 |
| 20 | 79792255837258801 |
| 21 | 558545832702224401 |