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 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 29 |
| 5 | 93 |
| 6 | 260 |
| 7 | 689 |
| 8 | 1845 |
| 9 | 5150 |
| 10 | 14897 |
| 11 | 43663 |
| 12 | 127451 |
| 13 | 368383 |
| 14 | 1056682 |
| 15 | 3022366 |
| 16 | 8651672 |
| 17 | 24818978 |
| 18 | 71319058 |
| 19 | 205070493 |
| 20 | 589550733 |
| 21 | 1694075057 |
| 22 | 4866102091 |
| 23 | 13975547842 |
| 24 | 40139685023 |
| 25 | 115298782211 |
| 26 | 331216158188 |
| 27 | 951506566087 |
| 28 | 2733431466995 |