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 | 4 |
| 3 | 11 |
| 4 | 30 |
| 5 | 85 |
| 6 | 244 |
| 7 | 715 |
| 8 | 2118 |
| 9 | 6317 |
| 10 | 18900 |
| 11 | 56635 |
| 12 | 169822 |
| 13 | 509365 |
| 14 | 1527972 |
| 15 | 4583771 |
| 16 | 13751142 |
| 17 | 41253229 |
| 18 | 123759460 |
| 19 | 371278123 |
| 20 | 1113834078 |
| 21 | 3341501909 |
| 22 | 10024505364 |
| 23 | 30073515691 |
| 24 | 90220546630 |
| 25 | 270661639405 |
| 26 | 811984917684 |
| 27 | 2435954752475 |
| 28 | 7307864256798 |
| 29 | 21923592769717 |
| 30 | 65770778308420 |
| 31 | 197312334924475 |