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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 11 |
| 3 | 170 |
| 4 | 939 |
| 5 | 8342 |
| 6 | 80092 |
| 7 | 614581 |
| 8 | 5271923 |
| 9 | 45832761 |
| 10 | 379419508 |
| 11 | 3223419241 |
| 12 | 27438555522 |
| 13 | 231096250072 |
| 14 | 1958024834151 |
| 15 | 16593169804557 |
| 16 | 140295718998907 |
| 17 | 1187830239559588 |
| 18 | 10056816580083721 |
| 19 | 85104482994177208 |
| 20 | 720410915948382970 |
| 21 | 6098207777286812381 |