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 | 4 |
| 4 | 10 |
| 5 | 29 |
| 6 | 88 |
| 7 | 281 |
| 8 | 928 |
| 9 | 3170 |
| 10 | 11108 |
| 11 | 39844 |
| 12 | 145700 |
| 13 | 542099 |
| 14 | 2047390 |
| 15 | 7837154 |
| 16 | 30359390 |
| 17 | 118877686 |
| 18 | 470023034 |
| 19 | 1874858180 |
| 20 | 7538907394 |
| 21 | 30538466279 |
| 22 | 124544812652 |
| 23 | 511112081854 |
| 24 | 2109676656860 |
| 25 | 8754763717529 |
| 26 | 36512355688438 |
| 27 | 152987775947396 |