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) |
|---|---|
| 12 | 1 |
| 13 | 13 |
| 14 | 91 |
| 15 | 455 |
| 16 | 1820 |
| 17 | 6188 |
| 18 | 18564 |
| 19 | 50388 |
| 20 | 125970 |
| 21 | 293930 |
| 22 | 646646 |
| 23 | 1352078 |
| 24 | 2704156 |
| 25 | 5200300 |
| 26 | 9657700 |
| 27 | 17383860 |
| 28 | 30421755 |
| 29 | 51895935 |
| 30 | 86493225 |
| 31 | 141120525 |
| 32 | 225792840 |
| 33 | 354817320 |
| 34 | 548354040 |
| 35 | 834451800 |
| 36 | 1251677700 |
| 37 | 1852482996 |
| 38 | 2707475148 |
| 39 | 3910797436 |
| 40 | 5586853480 |