| 0 ≤ j, 0 ≤ i, 0 < j, j ≤ i, j < i, 1 < i, 0 < i ⊦ fac(i) / (fac(i - j) * fac(j)) = fac(i - 1) / (fac(i - j) * fac(j - 1)) + fac(i - 1) / (fac(i - 1 + j) * fac(j)) |
fac(i - 1) / (fac(i - j) * fac(j - 1)) = (j * fac(i - 1)) / (fac(i - j) * fac(j)), 0 ≤ j, 0 ≤ i, 0 < j, j ≤ i, j < i, 1 < i, 0 < i ⊦ fac(i) / (fac(i - j) * fac(j)) = fac(i - 1) / (fac(i - j) * fac(j - 1)) + fac(i - 1) / (fac(i - 1 + j) * fac(j))
0 ≤ j, 0 ≤ i, 0 < j, j ≤ i, j < i, 1 < i, 0 < i ⊦ fac(i - 1) / (fac(i - j) * fac(j - 1)) = (j * fac(i - 1)) / (fac(i - j) * fac(j)), fac(i) / (fac(i - j) * fac(j)) = fac(i - 1) / (fac(i - j) * fac(j - 1)) + fac(i - 1) / (fac(i - 1 + j) * fac(j))
Used formulas: fac(i - 1) / (fac(i - j) * fac(j - 1)) = (j * fac(i - 1)) / (fac(i - j) * fac(j))