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 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 107 |
| 6 | 387 |
| 7 | 1415 |
| 8 | 5231 |
| 9 | 19477 |
| 10 | 72933 |
| 11 | 274339 |
| 12 | 1035807 |
| 13 | 3923229 |
| 14 | 14900005 |
| 15 | 56721943 |
| 16 | 216377047 |
| 17 | 826917803 |
| 18 | 3165318823 |
| 19 | 12133973901 |
| 20 | 46575395693 |
| 21 | 178988128029 |
| 22 | 688588254425 |
| 23 | 2651686966607 |
| 24 | 10220607799703 |
| 25 | 39426825300181 |