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 | 3 |
| 3 | 19 |
| 4 | 146 |
| 5 | 1129 |
| 6 | 9142 |
| 7 | 77025 |
| 8 | 664277 |
| 9 | 5837665 |
| 10 | 52064915 |
| 11 | 469864125 |
| 12 | 4281198201 |
| 13 | 39319600765 |
| 14 | 363545360347 |
| 15 | 3380562309312 |
| 16 | 31590949437540 |
| 17 | 296487794277035 |
| 18 | 2793170342851930 |
| 19 | 26402713858800478 |
| 20 | 250324979315879678 |
| 21 | 2379753569255122805 |
| 22 | 22678735843184786383 |