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 | 3 |
| 2 | 7 |
| 3 | 21 |
| 4 | 48 |
| 5 | 112 |
| 6 | 336 |
| 7 | 861 |
| 8 | 1968 |
| 9 | 4592 |
| 10 | 13776 |
| 11 | 33936 |
| 12 | 86961 |
| 13 | 198768 |
| 14 | 463792 |
| 15 | 1391376 |
| 16 | 3402672 |
| 17 | 8382192 |
| 18 | 21479367 |
| 19 | 49095696 |
| 20 | 114556624 |
| 21 | 343669872 |
| 22 | 852913488 |
| 23 | 2085837936 |
| 24 | 5138283696 |
| 25 | 13166851971 |
| 26 | 30095661648 |
| 27 | 70223210512 |