>>246
>>258 を解いて

P(n,k) = (1/10) + (1/5) r^{n/2} cos(2π(3.5n - k)/10)
      + (1/5) (r')^{n/2} cos(2π(4.5n + 3k)/10)
      + (1/2) (1/6)^n {δ_5(n-k) - (1/5)},
ここに
 r = (5+2√5) /36 = (√5) φ^3 /36 = 0.2631148876
 r' = (5-2√5) /36 = (√5) φ^{-3} /36 = 0.01466289014
 δ_5(n-k) = 1,  n-k≡0 (mod 5)
     = 0,  n-k≠0 (mod 5)