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 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 11 |
| 4 | 25 |
| 5 | 51 |
| 6 | 105 |
| 7 | 211 |
| 8 | 425 |
| 9 | 851 |
| 10 | 1705 |
| 11 | 3411 |
| 12 | 6825 |
| 13 | 13651 |
| 14 | 27305 |
| 15 | 54611 |
| 16 | 109225 |
| 17 | 218451 |
| 18 | 436905 |
| 19 | 873811 |
| 20 | 1747625 |
| 21 | 3495251 |
| 22 | 6990505 |
| 23 | 13981011 |
| 24 | 27962025 |
| 25 | 55924051 |
| 26 | 111848105 |
| 27 | 223696211 |
| 28 | 447392425 |
| 29 | 894784851 |
| 30 | 1789569705 |
| 31 | 3579139411 |