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 | 3 |
| 1 | 18 |
| 2 | 126 |
| 3 | 972 |
| 4 | 7938 |
| 5 | 67068 |
| 6 | 578826 |
| 7 | 5065092 |
| 8 | 44732898 |
| 9 | 397517868 |
| 10 | 3547309626 |
| 11 | 31744033812 |
| 12 | 284606850258 |
| 13 | 2554928116668 |
| 14 | 22955161402026 |
| 15 | 206361331428132 |
| 16 | 1855841341806018 |
| 17 | 16694108488251468 |
| 18 | 150196195641088026 |