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 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 19 |
| 6 | 46 |
| 7 | 108 |
| 8 | 273 |
| 9 | 696 |
| 10 | 1836 |
| 11 | 4896 |
| 12 | 13323 |
| 13 | 36541 |
| 14 | 101323 |
| 15 | 282693 |
| 16 | 793697 |
| 17 | 2237982 |
| 18 | 6335978 |
| 19 | 17992622 |
| 20 | 51235887 |
| 21 | 146228734 |
| 22 | 418181860 |
| 23 | 1197972026 |
| 24 | 3437159492 |
| 25 | 9875198568 |
| 26 | 28407202891 |
| 27 | 81807809714 |
| 28 | 235831978115 |
| 29 | 680478488927 |
| 30 | 1965160731704 |