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 | 12 |
| 2 | 66 |
| 3 | 255 |
| 4 | 903 |
| 5 | 2970 |
| 6 | 8571 |
| 7 | 23001 |
| 8 | 59763 |
| 9 | 145164 |
| 10 | 333693 |
| 11 | 751059 |
| 12 | 1623009 |
| 13 | 3363576 |
| 14 | 6872307 |
| 15 | 13677228 |
| 16 | 26351985 |
| 17 | 50309910 |
| 18 | 94392525 |
| 19 | 172538934 |
| 20 | 313558506 |
| 21 | 563064207 |
| 22 | 988996095 |
| 23 | 1730456433 |
| 24 | 3001805067 |
| 25 | 5106353439 |