>>544
　Memo.

漸化式は
　a_{n+1} = (1/2) {√(2x-1) - 1} s_n,
　s_{n+1} = s_n + a_{n+1},
　M_n = (n/3) (x-1),
ここに
　x = (1 + a_n/s_n)^2.

(例)

M_1 = 1
　a_1 = s_1 = 1

M_2 = 2(47-14√7)/27 = 0.7377393811182
　a_2 = (√7 -1)/2 = 0.8228756555323
　s_2 = (√7 +1)/2 = 1.8228756555323

M_3 = 0.64816160331616
　a_3 = 0.72235563718495
　s_3 = 2.54523129271725

M_4 = 0.60233351872589
　a_4 = 0.65585825517001
　s_4 = 3.20108954788726

M_5 = 0.57425545264547
　a_5 = 0.60768519695068
　s_5 = 3.80877474483794

M_6 = 0.55517800140267
　a_6 = 0.57066170678793
　s_6 = 4.37943645162587

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