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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 38 |
| 5 | 125 |
| 6 | 414 |
| 7 | 1369 |
| 8 | 4522 |
| 9 | 14934 |
| 10 | 49322 |
| 11 | 162899 |
| 12 | 538020 |
| 13 | 1776961 |
| 14 | 5868904 |
| 15 | 19383672 |
| 16 | 64019918 |
| 17 | 211443425 |
| 18 | 698350194 |
| 19 | 2306494009 |
| 20 | 7617832222 |
| 21 | 25159990674 |
| 22 | 83097804242 |
| 23 | 274453403399 |
| 24 | 906458014440 |