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 | 1 |
| 2 | 17 |
| 3 | 144 |
| 4 | 920 |
| 5 | 5191 |
| 6 | 27651 |
| 7 | 143342 |
| 8 | 733512 |
| 9 | 3730303 |
| 10 | 18914231 |
| 11 | 95766768 |
| 12 | 484557538 |
| 13 | 2450951157 |
| 14 | 12395284963 |
| 15 | 62682479764 |
| 16 | 316971668262 |
| 17 | 1602829696167 |
| 18 | 8104958759329 |
| 19 | 40983832221302 |
| 20 | 207239970377650 |
| 21 | 1047934399198859 |