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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 8 |
| 10 | 36 |
| 11 | 120 |
| 12 | 330 |
| 13 | 792 |
| 14 | 1716 |
| 15 | 3432 |
| 16 | 48477 |
| 17 | 368797 |
| 18 | 2002429 |
| 19 | 8685469 |
| 20 | 31964725 |
| 21 | 103593205 |
| 22 | 303129685 |
| 23 | 6156709438 |
| 24 | 66139517554 |
| 25 | 498859498016 |
| 26 | 2961422519550 |
| 27 | 14715247475500 |
| 28 | 63593705003400 |
| 29 | 245316996896400 |
| 30 | 6498850067259615 |