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 | 0 |
| 2 | 37 |
| 3 | 197 |
| 4 | 1369 |
| 5 | 8991 |
| 6 | 59705 |
| 7 | 395641 |
| 8 | 2622817 |
| 9 | 17385993 |
| 10 | 115249117 |
| 11 | 763966685 |
| 12 | 5064207645 |
| 13 | 33569783613 |
| 14 | 222528473325 |
| 15 | 1475103973253 |
| 16 | 9778217146445 |
| 17 | 64818163521317 |
| 18 | 429668748357261 |
| 19 | 2848202159470085 |
| 20 | 18880255015594493 |