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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 15 |
| 6 | 36 |
| 7 | 94 |
| 8 | 245 |
| 9 | 663 |
| 10 | 1815 |
| 11 | 5062 |
| 12 | 14269 |
| 13 | 40706 |
| 14 | 117103 |
| 15 | 339673 |
| 16 | 991834 |
| 17 | 2913869 |
| 18 | 8605576 |
| 19 | 25536300 |
| 20 | 76096896 |
| 21 | 227634717 |
| 22 | 683296679 |
| 23 | 2057540487 |
| 24 | 6213495745 |
| 25 | 18813535942 |
| 26 | 57103173296 |
| 27 | 173710272584 |
| 28 | 529534793886 |
| 29 | 1617347972250 |
| 30 | 4948744120771 |