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 | 3 |
| 2 | 6 |
| 3 | 12 |
| 4 | 28 |
| 5 | 63 |
| 6 | 144 |
| 7 | 330 |
| 8 | 755 |
| 9 | 1728 |
| 10 | 3957 |
| 11 | 9058 |
| 12 | 20736 |
| 13 | 47474 |
| 14 | 108688 |
| 15 | 248832 |
| 16 | 569684 |
| 17 | 1304249 |
| 18 | 2985984 |
| 19 | 6836197 |
| 20 | 15650984 |
| 21 | 35831808 |
| 22 | 82034362 |
| 23 | 187811805 |
| 24 | 429981696 |
| 25 | 984412343 |
| 26 | 2253741659 |
| 27 | 5159780352 |
| 28 | 11812948115 |
| 29 | 27044899908 |
| 30 | 61917364224 |