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) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 13 |
| 4 | 38 |
| 5 | 94 |
| 6 | 213 |
| 7 | 459 |
| 8 | 960 |
| 9 | 1972 |
| 10 | 4007 |
| 11 | 8089 |
| 12 | 16266 |
| 13 | 32634 |
| 14 | 65385 |
| 15 | 130903 |
| 16 | 261956 |
| 17 | 524080 |
| 18 | 1048347 |
| 19 | 2096901 |
| 20 | 4194030 |
| 21 | 8388310 |
| 22 | 16776893 |
| 23 | 33554083 |
| 24 | 67108488 |
| 25 | 134217324 |
| 26 | 268435023 |
| 27 | 536870449 |
| 28 | 1073741330 |
| 29 | 2147483122 |
| 30 | 4294966737 |
| 31 | 8589933999 |
| 32 | 17179868556 |
| 33 | 34359737704 |
| 34 | 68719476035 |
| 35 | 137438952733 |
| 36 | 274877906166 |
| 37 | 549755813070 |
| 38 | 1099511626917 |
| 39 | 2199023254651 |
| 40 | 4398046510160 |