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 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 10 |
| 5 | 33 |
| 6 | 104 |
| 7 | 328 |
| 8 | 1031 |
| 9 | 3241 |
| 10 | 10183 |
| 11 | 31991 |
| 12 | 100503 |
| 13 | 315740 |
| 14 | 991928 |
| 15 | 3116234 |
| 16 | 9789941 |
| 17 | 30756009 |
| 18 | 96622854 |
| 19 | 303549648 |
| 20 | 953629346 |
| 21 | 2995914948 |
| 22 | 9411944394 |
| 23 | 29568495367 |
| 24 | 92892167824 |
| 25 | 291829352014 |
| 26 | 916808948392 |
| 27 | 2880240257014 |