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 | 4 |
| 2 | 9 |
| 3 | 20 |
| 4 | 46 |
| 5 | 103 |
| 6 | 233 |
| 7 | 525 |
| 8 | 1182 |
| 9 | 2660 |
| 10 | 5985 |
| 11 | 13467 |
| 12 | 30301 |
| 13 | 68178 |
| 14 | 153401 |
| 15 | 345152 |
| 16 | 776591 |
| 17 | 1747331 |
| 18 | 3931496 |
| 19 | 8845866 |
| 20 | 19903198 |
| 21 | 44782196 |
| 22 | 100759940 |
| 23 | 226709866 |
| 24 | 510097200 |
| 25 | 1147718700 |
| 26 | 2582367076 |
| 27 | 5810325920 |
| 28 | 13073233321 |
| 29 | 29414774973 |