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 | 13 |
| 3 | 141 |
| 4 | 1017 |
| 5 | 5671 |
| 6 | 36695 |
| 7 | 274919 |
| 8 | 1905346 |
| 9 | 11961897 |
| 10 | 70484777 |
| 11 | 393138130 |
| 12 | 2099243511 |
| 13 | 11182203514 |
| 14 | 61491912211 |
| 15 | 342906589613 |
| 16 | 1849155959180 |
| 17 | 9348828582989 |
| 18 | 44293571012946 |
| 19 | 201612389814511 |
| 20 | 924729895792089 |
| 21 | 4608967720196409 |
| 22 | 26924559367277143 |