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 | 36 |
| 3 | 486 |
| 4 | 3888 |
| 5 | 24300 |
| 6 | 131220 |
| 7 | 642978 |
| 8 | 2939328 |
| 9 | 12754584 |
| 10 | 53144100 |
| 11 | 214347870 |
| 12 | 841802544 |
| 13 | 3233287044 |
| 14 | 12187005012 |
| 15 | 45199057050 |
| 16 | 165299408640 |
| 17 | 597144113712 |
| 18 | 2133912053412 |
| 19 | 7552375012566 |
| 20 | 26499561447600 |
| 21 | 92260315250460 |