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 | 4 |
| 1 | 15 |
| 2 | 40 |
| 3 | 93 |
| 4 | 202 |
| 5 | 423 |
| 6 | 868 |
| 7 | 1761 |
| 8 | 3550 |
| 9 | 7131 |
| 10 | 14296 |
| 11 | 28629 |
| 12 | 57298 |
| 13 | 114639 |
| 14 | 229324 |
| 15 | 458697 |
| 16 | 917446 |
| 17 | 1834947 |
| 18 | 3669952 |
| 19 | 7339965 |
| 20 | 14679994 |
| 21 | 29360055 |
| 22 | 58720180 |
| 23 | 117440433 |
| 24 | 234880942 |
| 25 | 469761963 |
| 26 | 939524008 |
| 27 | 1879048101 |
| 28 | 3758096290 |
| 29 | 7516192671 |
| 30 | 15032385436 |