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 | 2 |
| 2 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 16 |
| 6 | 41 |
| 7 | 110 |
| 8 | 304 |
| 9 | 858 |
| 10 | 2474 |
| 11 | 7234 |
| 12 | 21418 |
| 13 | 64057 |
| 14 | 193277 |
| 15 | 587531 |
| 16 | 1797817 |
| 17 | 5532916 |
| 18 | 17115442 |
| 19 | 53186682 |
| 20 | 165958893 |
| 21 | 519764706 |
| 22 | 1633331926 |
| 23 | 5148420607 |
| 24 | 16273962742 |
| 25 | 51574291758 |
| 26 | 163834983761 |
| 27 | 521597902077 |
| 28 | 1663993969029 |
| 29 | 5318540288800 |
| 30 | 17029516243797 |