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) |
|---|---|
| 0 | 1 |
| 1 | 70 |
| 2 | 2415 |
| 3 | 54740 |
| 4 | 916895 |
| 5 | 12103014 |
| 6 | 131115985 |
| 7 | 1198774720 |
| 8 | 9440350920 |
| 9 | 65033528560 |
| 10 | 396704524216 |
| 11 | 2163842859360 |
| 12 | 10638894058520 |
| 13 | 47465835030320 |
| 14 | 193253756909160 |
| 15 | 721480692460864 |
| 16 | 2480089880334220 |
| 17 | 7877932561061640 |
| 18 | 23196134763125940 |