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) |
|---|---|
| 4 | 1 |
| 5 | 31 |
| 6 | 651 |
| 7 | 11811 |
| 8 | 200787 |
| 9 | 3309747 |
| 10 | 53743987 |
| 11 | 866251507 |
| 12 | 13910980083 |
| 13 | 222984027123 |
| 14 | 3571013994483 |
| 15 | 57162391576563 |
| 16 | 914807651274739 |
| 17 | 14638597687734259 |
| 18 | 234230965858250739 |
| 19 | 3747802679431278579 |
| 20 | 59965700687947706355 |
| 21 | 959458073589354016755 |
| 22 | 15351384078270441402355 |