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 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 12 |
| 5 | 55 |
| 6 | 246 |
| 7 | 474 |
| 8 | 2107 |
| 9 | 9360 |
| 10 | 18018 |
| 11 | 80029 |
| 12 | 355452 |
| 13 | 684228 |
| 14 | 3039013 |
| 15 | 13497834 |
| 16 | 25982664 |
| 17 | 115402483 |
| 18 | 512562258 |
| 19 | 986657022 |
| 20 | 4382255359 |
| 21 | 19463867988 |
| 22 | 37466984190 |
| 23 | 166410301177 |
| 24 | 739114421304 |
| 25 | 1422758742216 |
| 26 | 6319209189385 |
| 27 | 28066884141582 |
| 28 | 54027365220036 |
| 29 | 239963538895471 |
| 30 | 1065802482958830 |
| 31 | 2051617119619170 |