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 | 5 |
| 2 | 17 |
| 3 | 52 |
| 4 | 152 |
| 5 | 435 |
| 6 | 1232 |
| 7 | 3471 |
| 8 | 9753 |
| 9 | 27367 |
| 10 | 76738 |
| 11 | 215098 |
| 12 | 602811 |
| 13 | 1689212 |
| 14 | 4733317 |
| 15 | 13262821 |
| 16 | 37162121 |
| 17 | 104126704 |
| 18 | 291757632 |
| 19 | 817488295 |
| 20 | 2290553580 |
| 21 | 6417991803 |
| 22 | 17982818177 |
| 23 | 50386743719 |
| 24 | 141180528542 |
| 25 | 395579064834 |
| 26 | 1108387929991 |
| 27 | 3105633996920 |
| 28 | 8701793132873 |
| 29 | 24381882610741 |