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 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -2 |
| 5 | 3 |
| 6 | 1 |
| 7 | -3 |
| 8 | 6 |
| 9 | -10 |
| 10 | 1 |
| 11 | -4 |
| 12 | 10 |
| 13 | -20 |
| 14 | 35 |
| 15 | 1 |
| 16 | -5 |
| 17 | 15 |
| 18 | -35 |
| 19 | 70 |
| 20 | -126 |
| 21 | 1 |
| 22 | -6 |
| 23 | 21 |
| 24 | -56 |
| 25 | 126 |
| 26 | -252 |
| 27 | 462 |
| 28 | 1 |
| 29 | -7 |
| 30 | 28 |
| 31 | -84 |
| 32 | 210 |
| 33 | -462 |
| 34 | 924 |
| 35 | -1716 |
| 36 | 1 |
| 37 | -8 |
| 38 | 36 |
| 39 | -120 |
| 40 | 330 |
| 41 | -792 |
| 42 | 1716 |
| 43 | -3432 |
| 44 | 6435 |
| 45 | 1 |
| 46 | -9 |
| 47 | 45 |
| 48 | -165 |
| 49 | 495 |
| 50 | -1287 |
| 51 | 3003 |
| 52 | -6435 |
| 53 | 12870 |
| 54 | -24310 |
| 55 | 1 |
| 56 | -10 |
| 57 | 55 |
| 58 | -220 |
| 59 | 715 |
| 60 | -2002 |
| 61 | 5005 |
| 62 | -11440 |
| 63 | 24310 |
| 64 | -48620 |
| 65 | 92378 |