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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 18 |
| 6 | 34 |
| 7 | 62 |
| 8 | 118 |
| 9 | 222 |
| 10 | 432 |
| 11 | 834 |
| 12 | 1642 |
| 13 | 3230 |
| 14 | 6406 |
| 15 | 12702 |
| 16 | 25298 |
| 17 | 50386 |
| 18 | 100566 |
| 19 | 200716 |
| 20 | 401022 |
| 21 | 801230 |
| 22 | 1601654 |
| 23 | 3201694 |
| 24 | 6401784 |
| 25 | 12800378 |
| 26 | 25597578 |
| 27 | 51188806 |
| 28 | 102371284 |
| 29 | 204729938 |
| 30 | 409447272 |
| 31 | 818869352 |
| 32 | 1637713546 |
| 33 | 3275376848 |
| 34 | 6550703506 |
| 35 | 13101306654 |
| 36 | 26202513022 |
| 37 | 52404825604 |
| 38 | 104809450870 |
| 39 | 209618501128 |
| 40 | 419236601774 |