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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 42 |
| 6 | 140 |
| 7 | 473 |
| 8 | 1670 |
| 9 | 5969 |
| 10 | 21679 |
| 11 | 79419 |
| 12 | 293496 |
| 13 | 1091006 |
| 14 | 4078213 |
| 15 | 15312150 |
| 16 | 57721030 |
| 17 | 218333832 |
| 18 | 828408842 |
| 19 | 3151769615 |
| 20 | 12020870753 |
| 21 | 45949957412 |
| 22 | 176001205559 |
| 23 | 675384194565 |
| 24 | 2596119292840 |
| 25 | 9994894356158 |
| 26 | 38535398284100 |
| 27 | 148772774499015 |
| 28 | 575079507042663 |