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 | 3 |
| 2 | 7 |
| 3 | 15 |
| 4 | 26 |
| 5 | 57 |
| 6 | 128 |
| 7 | 319 |
| 8 | 849 |
| 9 | 2285 |
| 10 | 6395 |
| 11 | 18072 |
| 12 | 51914 |
| 13 | 150497 |
| 14 | 439554 |
| 15 | 1292568 |
| 16 | 3819778 |
| 17 | 11341738 |
| 18 | 33806234 |
| 19 | 101113152 |
| 20 | 303345648 |
| 21 | 912494104 |
| 22 | 2751564993 |
| 23 | 8315282765 |
| 24 | 25179029388 |
| 25 | 76381806785 |
| 26 | 232094778772 |
| 27 | 706331084162 |
| 28 | 2152626447195 |
| 29 | 6569037508556 |