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 | 10 |
| 4 | 33 |
| 5 | 110 |
| 6 | 366 |
| 7 | 1219 |
| 8 | 4059 |
| 9 | 13518 |
| 10 | 45018 |
| 11 | 149924 |
| 12 | 499290 |
| 13 | 1662787 |
| 14 | 5537577 |
| 15 | 18441799 |
| 16 | 61416729 |
| 17 | 204536183 |
| 18 | 681166986 |
| 19 | 2268490929 |
| 20 | 7554756990 |
| 21 | 25159612832 |
| 22 | 83789077212 |
| 23 | 279042826065 |
| 24 | 929296530558 |
| 25 | 3094836925438 |