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 | 9 |
| 2 | 40 |
| 3 | 163 |
| 4 | 606 |
| 5 | 2149 |
| 6 | 7378 |
| 7 | 24767 |
| 8 | 81784 |
| 9 | 266721 |
| 10 | 861426 |
| 11 | 2760523 |
| 12 | 8790108 |
| 13 | 27841469 |
| 14 | 87789916 |
| 15 | 275762167 |
| 16 | 863353934 |
| 17 | 2695201705 |
| 18 | 8392538682 |
| 19 | 26074810851 |
| 20 | 80850124228 |
| 21 | 250242934405 |
| 22 | 773288315888 |
| 23 | 2386084417999 |