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 | 13 |
| 4 | 27 |
| 5 | 57 |
| 6 | 119 |
| 7 | 250 |
| 8 | 523 |
| 9 | 1097 |
| 10 | 2297 |
| 11 | 4815 |
| 12 | 10086 |
| 13 | 21137 |
| 14 | 44283 |
| 15 | 92793 |
| 16 | 194419 |
| 17 | 407378 |
| 18 | 853559 |
| 19 | 1788481 |
| 20 | 3747361 |
| 21 | 7851867 |
| 22 | 16451910 |
| 23 | 34471669 |
| 24 | 72228171 |
| 25 | 151339401 |
| 26 | 317100335 |
| 27 | 664418698 |
| 28 | 1392152131 |