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 | 7 |
| 3 | 19 |
| 4 | 51 |
| 5 | 135 |
| 6 | 361 |
| 7 | 963 |
| 8 | 2570 |
| 9 | 6859 |
| 10 | 18303 |
| 11 | 48839 |
| 12 | 130321 |
| 13 | 347749 |
| 14 | 927933 |
| 15 | 2476099 |
| 16 | 6607227 |
| 17 | 17630734 |
| 18 | 47045881 |
| 19 | 125537306 |
| 20 | 334983955 |
| 21 | 893871739 |
| 22 | 2385208822 |
| 23 | 6364695153 |
| 24 | 16983563041 |
| 25 | 45318967620 |
| 26 | 120929207915 |
| 27 | 322687697779 |
| 28 | 861060384776 |
| 29 | 2297654950385 |