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 | 30 |
| 2 | 490 |
| 3 | 3010 |
| 4 | 12310 |
| 5 | 715220 |
| 6 | 831820 |
| 7 | 1741630 |
| 8 | 2323520 |
| 9 | 7089500 |
| 10 | 13848650 |
| 11 | 26543660 |
| 12 | 92669720 |
| 13 | 133230930 |
| 14 | 271248950 |
| 15 | 541946240 |
| 16 | 1844349560 |
| 17 | 2841940500 |
| 18 | 4351078600 |
| 19 | 4835271870 |
| 20 | 5371315400 |
| 21 | 10015581680 |
| 22 | 18440293320 |
| 23 | 37027355200 |