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 | 7 |
| 2 | 55 |
| 3 | 472 |
| 4 | 4300 |
| 5 | 40861 |
| 6 | 400567 |
| 7 | 4021720 |
| 8 | 41147398 |
| 9 | 427470430 |
| 10 | 4497253054 |
| 11 | 47817544348 |
| 12 | 513029453530 |
| 13 | 5547155801065 |
| 14 | 60385754935495 |
| 15 | 661267785740080 |
| 16 | 7279524885630310 |
| 17 | 80512572260496610 |
| 18 | 894231158402339410 |