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 | 4 |
| 3 | 13 |
| 4 | 41 |
| 5 | 125 |
| 6 | 374 |
| 7 | 1103 |
| 8 | 3213 |
| 9 | 9259 |
| 10 | 26430 |
| 11 | 74806 |
| 12 | 210095 |
| 13 | 585890 |
| 14 | 1623240 |
| 15 | 4470232 |
| 16 | 12241799 |
| 17 | 33349751 |
| 18 | 90410255 |
| 19 | 243977941 |
| 20 | 655553258 |
| 21 | 1754265279 |
| 22 | 4676358086 |
| 23 | 12420299846 |
| 24 | 32873598566 |
| 25 | 86721264126 |
| 26 | 228051843891 |
| 27 | 597905347237 |
| 28 | 1563071037798 |
| 29 | 4074973824099 |