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 | 11 |
| 3 | 86 |
| 4 | 519 |
| 5 | 3626 |
| 6 | 26167 |
| 7 | 185810 |
| 8 | 1317541 |
| 9 | 9353154 |
| 10 | 66404553 |
| 11 | 471405566 |
| 12 | 3346494089 |
| 13 | 23756835310 |
| 14 | 168650322345 |
| 15 | 1197251824916 |
| 16 | 8499313431065 |
| 17 | 60336790015098 |
| 18 | 428332035511083 |
| 19 | 3040737367321452 |
| 20 | 21586253123647687 |