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 | 6 |
| 2 | 15 |
| 3 | 30 |
| 4 | 105 |
| 5 | 210 |
| 6 | 705 |
| 7 | 1290 |
| 8 | 4410 |
| 9 | 7740 |
| 10 | 26985 |
| 11 | 46650 |
| 12 | 162435 |
| 13 | 279930 |
| 14 | 978465 |
| 15 | 1679370 |
| 16 | 5874120 |
| 17 | 10077690 |
| 18 | 35263440 |
| 19 | 60466170 |
| 20 | 211604295 |
| 21 | 362795730 |
| 22 | 1269743025 |
| 23 | 2176782330 |
| 24 | 7618570470 |
| 25 | 13060693800 |