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 | 5 |
| 4 | 12 |
| 5 | 29 |
| 6 | 70 |
| 7 | 170 |
| 8 | 410 |
| 9 | 990 |
| 10 | 2390 |
| 11 | 5770 |
| 12 | 13930 |
| 13 | 33630 |
| 14 | 81190 |
| 15 | 196010 |
| 16 | 473210 |
| 17 | 1142430 |
| 18 | 2758070 |
| 19 | 6658570 |
| 20 | 16075210 |
| 21 | 38808990 |
| 22 | 93693190 |
| 23 | 226195370 |
| 24 | 546083930 |
| 25 | 1318363230 |
| 26 | 3182810390 |
| 27 | 7683984010 |
| 28 | 18550778410 |
| 29 | 44785540830 |
| 30 | 108121860070 |