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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 15 |
| 5 | 44 |
| 6 | 126 |
| 7 | 374 |
| 8 | 1106 |
| 9 | 3307 |
| 10 | 9877 |
| 11 | 29599 |
| 12 | 88675 |
| 13 | 265932 |
| 14 | 797453 |
| 15 | 2392089 |
| 16 | 7175294 |
| 17 | 21525097 |
| 18 | 64572513 |
| 19 | 193715253 |
| 20 | 581137787 |
| 21 | 1743406694 |
| 22 | 5230197111 |
| 23 | 15690571861 |
| 24 | 47071649170 |
| 25 | 141214890563 |
| 26 | 423644479136 |
| 27 | 1270933270658 |
| 28 | 3812799252359 |
| 29 | 11438397268254 |
| 30 | 34315190174990 |