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 | 1 |
| 3 | 7 |
| 4 | 25 |
| 5 | 61 |
| 6 | 187 |
| 7 | 666 |
| 8 | 2137 |
| 9 | 6676 |
| 10 | 22001 |
| 11 | 73217 |
| 12 | 239923 |
| 13 | 789517 |
| 14 | 2624182 |
| 15 | 8729527 |
| 16 | 29026553 |
| 17 | 96790606 |
| 18 | 323546416 |
| 19 | 1082566763 |
| 20 | 3626148425 |
| 21 | 12163438539 |
| 22 | 40847087821 |
| 23 | 137294721676 |
| 24 | 461890741843 |
| 25 | 1555264438186 |
| 26 | 5240857508017 |
| 27 | 17672768973979 |
| 28 | 59634361740734 |