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 | 0 |
| 1 | 15 |
| 2 | 120 |
| 3 | 435 |
| 4 | 1128 |
| 5 | 2415 |
| 6 | 4560 |
| 7 | 7875 |
| 8 | 12720 |
| 9 | 19503 |
| 10 | 28680 |
| 11 | 40755 |
| 12 | 56280 |
| 13 | 75855 |
| 14 | 100128 |
| 15 | 129795 |
| 16 | 165600 |
| 17 | 208335 |
| 18 | 258840 |
| 19 | 318003 |
| 20 | 386760 |
| 21 | 466095 |
| 22 | 557040 |
| 23 | 660675 |
| 24 | 778128 |
| 25 | 910575 |
| 26 | 1059240 |
| 27 | 1225395 |
| 28 | 1410360 |
| 29 | 1615503 |
| 30 | 1842240 |
| 31 | 2092035 |