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 | 0 |
| 2 | 3 |
| 3 | 14 |
| 4 | 49 |
| 5 | 148 |
| 6 | 427 |
| 7 | 1170 |
| 8 | 3150 |
| 9 | 8288 |
| 10 | 21562 |
| 11 | 55368 |
| 12 | 140998 |
| 13 | 355854 |
| 14 | 892014 |
| 15 | 2220856 |
| 16 | 5497483 |
| 17 | 13533264 |
| 18 | 33150801 |
| 19 | 80825768 |
| 20 | 196218139 |
| 21 | 474423934 |
| 22 | 1142756063 |
| 23 | 2742781794 |
| 24 | 6561049181 |
| 25 | 15645058210 |
| 26 | 37194447065 |
| 27 | 88174246904 |
| 28 | 208463588035 |
| 29 | 491585765888 |