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) |
|---|---|
| 3 | 1 |
| 4 | 14 |
| 5 | 115 |
| 6 | 640 |
| 7 | 3049 |
| 8 | 13494 |
| 9 | 57491 |
| 10 | 239768 |
| 11 | 986976 |
| 12 | 4027666 |
| 13 | 16335660 |
| 14 | 65955960 |
| 15 | 265386251 |
| 16 | 1064993622 |
| 17 | 4264898875 |
| 18 | 17051078256 |
| 19 | 68080259516 |
| 20 | 271537515786 |
| 21 | 1082098938452 |
| 22 | 4309269809044 |
| 23 | 17151303222746 |
| 24 | 68232856509950 |
| 25 | 271350536990740 |
| 26 | 1078796298028680 |
| 27 | 4287906741748940 |