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 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 84 |
| 6 | 592 |
| 7 | 4670 |
| 8 | 40108 |
| 9 | 368670 |
| 10 | 3586321 |
| 11 | 36632763 |
| 12 | 390694000 |
| 13 | 4332131804 |
| 14 | 49777965585 |
| 15 | 591173511887 |
| 16 | 7241437905916 |
| 17 | 91331043654080 |
| 18 | 1184322726542850 |
| 19 | 15770586926609276 |
| 20 | 215423253906689779 |
| 21 | 3015794930248824111 |
| 22 | 43233248160139146114 |