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 | 5 |
| 2 | 15 |
| 3 | 45 |
| 4 | 235 |
| 5 | 505 |
| 6 | 745 |
| 7 | 1415 |
| 8 | 1485 |
| 9 | 4495 |
| 10 | 5005 |
| 11 | 15985 |
| 12 | 50005 |
| 13 | 72495 |
| 14 | 469255 |
| 15 | 500005 |
| 16 | 500505 |
| 17 | 1597505 |
| 18 | 1598515 |
| 19 | 4474955 |
| 20 | 5000005 |
| 21 | 5000505 |
| 22 | 5050005 |
| 23 | 7085235 |
| 24 | 15008515 |
| 25 | 44949995 |
| 26 | 50000005 |
| 27 | 50000505 |
| 28 | 50005005 |
| 29 | 50500005 |
| 30 | 500000005 |
| 31 | 500000505 |
| 32 | 500005005 |
| 33 | 500254955 |
| 34 | 500500005 |