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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 17 |
| 5 | 43 |
| 6 | 111 |
| 7 | 291 |
| 8 | 771 |
| 9 | 2059 |
| 10 | 5533 |
| 11 | 14943 |
| 12 | 40523 |
| 13 | 110271 |
| 14 | 300949 |
| 15 | 823417 |
| 16 | 2257877 |
| 17 | 6203239 |
| 18 | 17071779 |
| 19 | 47054475 |
| 20 | 129872499 |
| 21 | 358896927 |
| 22 | 992907525 |
| 23 | 2749737663 |
| 24 | 7622185263 |
| 25 | 21146597511 |
| 26 | 58714466733 |
| 27 | 163142652877 |
| 28 | 453612137587 |
| 29 | 1262048222181 |
| 30 | 3513361583965 |