排容原理:
a1, a2, a3, a4分別代表出現{1, 2, 4, 5}塗黑、{2, 3, 5, 6}塗黑、{4, 5, 7, 8}塗黑、{5, 6, 8, 9}塗黑的性質
S = 2^9,
N(a1) = 2^5, N(a2) = 2^5, N(a3) = 2^5, N(a4) = 2^5,
N(a1a2) = 2^3, N(a2a3) = 2^3, N(a3a4) = 2^3, N(a4a1) = 2^3, , N(a1a3) = 2^3, N(a2a4) = 2^3,
N(a1a2a3) = 2^1, N(a2a3a4) = 2^1, N(a1a3a4) = 2^1, N(a1a2a4) = 2^1,
N(a1a2a3a4) = 2^0,
可能數 = 2^9 - 4*2^5 + 6*2^3 - 4*2^1 + 2^0
機率會自己算吧