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 | 1 |
| 2 | 9 |
| 3 | 36 |
| 4 | 148 |
| 5 | 489 |
| 6 | 1959 |
| 7 | 6326 |
| 8 | 22741 |
| 9 | 74072 |
| 10 | 246436 |
| 11 | 781189 |
| 12 | 2523042 |
| 13 | 7773342 |
| 14 | 24200874 |
| 15 | 73439472 |
| 16 | 222247101 |
| 17 | 660405663 |
| 18 | 1958564056 |
| 19 | 5715567301 |
| 20 | 16623600991 |
| 21 | 47780474694 |
| 22 | 136623175876 |
| 23 | 386983158080 |
| 24 | 1090779014163 |
| 25 | 3048348195528 |
| 26 | 8478106666045 |